xbSocket | Complete object-oriented sockets library that provides a protocol-independent | base for developing virtually any kind of communications software. | +-- xbServer (derived from: xbSocket, Thread) | | A generic protocol-independent server that can be easily configured for a | | variety of Telnet applications. | | | +-- xbHTTPServer (derived from: xbServer) | A powerful object-oriented HTTP 1.1 web and SOAP server that is build right into your | Xbase++ application. No need to configure and manage complex 3P web servers, | gateways and CGI scripts. Your Xbase++ program is the server! | +-- xbSocketThread (derived from: xbSocket, Thread) | This is the client thread that is spawned by xbServer when a connection with a peer | is accepted. This "worker" thread will handle the request and send a response back | to the connected client. | +-- xbHTTPThread (derived from: xbSocket, Thread) This is the client thread that is spawned by xbHTTPServer when a connection is accepted from a user agent (a browser). This "worker" thread is responsible for handling the client request and generating an appropriate xbHTTPResponse that will be sent back to the client. xbHTTPMessage | An abstract class for composing and parsing HTTP messages. | +-- xbHTTPRequest (derived from: xbHTTPMessage, xbURI) | Client side: Compose HTTP request and send to HTTP server. | Server side: Parse HTTP request received from client. | +-- xbHTTPResponse (derived from: xbHTTPMessage) Client side: Parse HTTP response received from server. Server side: Compose HTTP response and send to client. xbHTTPClient | Provides a higher level interface for developing HTTP client applications. | +-- xbXMLDocument (derived from: xbHTTPClient) | This class provides a simplified means for generating XML requests and parsing XML responses. | +-- xbSOAPEnvelope (derived from: xbHTTPClient) This class provides the code necessary to generate and parse SOAP messages. SOAP is a remote procedure calling protocol that encodes requests and responses in XML format. Using SOAP a client can execute methods or functions on a server and receive an XML response containing the return values. xbComplexType Used to represent complex data structures. Data structures can be nested, and may contain any other type, including an array. Instances of xbComplexType are typically used by the xbSOAPEnvelope class to serialize and deserialize complex data structures. xbForm This class represents a url-encoded form. The form typically contains data expressed as "name=value" pairs, encoded for safe transport over the net. This class allows you to parse an existing form as well as create a brand new form. xbFTPClient FTP (File Transfer Protocol) client provides methods for managing directories and files on a remote FTP or FTPS server. The class is fully compliant with RFC's 959, 2228 and 4217. It provides support for AUTH TLS, AUTH SSL and Implicit SSL connections. xbPayload Provides methods for serializing and deserializing one or more attachments of any size (files, character strings, objects or any Xbase++ data) for transmission between an HTTP client and server. This class is also used by the xbSOAPEnvelope class for sending SOAP attachments. xbSSLContext Provides a context for implementing secure network communications using the OpenSSL library. Once initialized, an xbSSLContext object can be attached to an xbSocket, xbServer, xbHTTPServer, xbHTTPClient, xbXMLDocument or xbSOAPEnvelope instance to provide secure communications. xbSession HTTP by nature is stateless and in itself provides limited session management capability. This class simplifies session management and provides the ability of saving persistent data across multiple HTTP requests. Sessions are automatically managed by the xbHTTPServer class. xbStream Provides generic methods for reading and writing to data stream files. xbTLog Class for logging client requests using Extended Log File Format (W3C Working Draft WD-logfile-960323). This log format is compatible with Microsoft Internet Information Server (IIS) and is supported by many third party web log analyzers. xbURI Create, parse, encode and decode URI and URL strings.
xbErrorLog( xError, [nErrorCode], [lisSSL], [cFile], [lFlash], [lLogCallstack] ) -> NIL
This function will log an error or event to a file. It is typically called from within an xbSocket:OnError codeblock.
Parameters:
xError
This parameter specifies the type of event that will be logged. The options are as follows:
- An error object, derived from the Xbase++ "Error" class.
- An object derived from the "xbSocket" class.
- A character string.
nErrorCode
The WinSock or OpenSSL error code number.
lisSSL
A logical value, which when set to .T., indicates that the error was raised by the OpenSSL library.
cFile
The name of the file where the information will be logged. If not specified, the default is xbSocket():ErrorLogFile.
lFlash
An optional logical value that is used to provide visual feedback of the error. When set to .T., the error message will
be briefly flashed on the display screen. The default is .F., meaning that no visual feedback is provided.
lLogCallstack
An optional logical value specifying if the callstack will be written to the file. The default is to log the callstack,
however this can be turned off by setting this parameter to .F.
xbCreateGuid() -> cGuid
Returns a globally unique identifier as a 36-character (hex) string in the following format
"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", eg:
6B29FC40-CA47-1067-B31D-00DD010662DA
When the originating computer does not have an ethernet/token ring address, the generated ID is only guaranteed to be
unique among all IDs generated on the same computer. Although very small, the possibility however does exists that
another computer without an ethernet/token ring address generated the identical ID. Computers with ethernet/token
ring addresses generate GUIDs that are guaranteed to be globally unique.
xbGetFileMimeType( cFileName ) -> cMimeType
Return the MIME media type for a given file name. The MIME media type is determined by file name's 3 or 4 character
extension. For example; file names with the extension .HTM will have a MIME media type of "text/html".
xbGetTickCount() -> nMilliseconds
Return the number of milliseconds that have elapsed since the system was started. The maximum return value is
limited to a 32 bit integer therefore, the time will wrap around to zero if the system is run continuously for
49.7 days.
xbGMTDate( [dDate], [cnTime] ) -> cGMTDate
Return a string representing the date and time in GMT using Internet conventions in the following form:
Day, DD Mon YYYY HH:MM:SS GMT, eg:
Wed, 07 Oct 2004 19:23:50 GMT
Both parameters are optional if not specified the current date/time is used. cnTime can be a numeric as returned by SECONDS(), or a string as returned by TIME(). The timezone is based on the return value of xbTimezoneOffset(). xbHTTPErrorHandler( oError, [cFile], [lLogError] ) -> cErrorMessage This is the default HTTP error handler that will be used in the absence of an xbHTTPServer:onHTTPError codeblock. The function is evaluated when a runtime error occurs during the processing of an HTTP request. It will log the error to a file, prepare an HTML error message and send it to the client. The function returns the HTML formatted string that will be sent to the client. Parameters: oError An Xbase++ error object. cFile The name of the file where the error will be logged. If not specified, the default is xbSocket():ErrorLogFile. lLogError An optional logical value that determines whether the error is logged to a file. The default behavior is to log the error to a file, however this can be disabled by setting lLogError to .F.
Example:
// use default error handler but don't log errors:
oServer:onHTTPError := {|oError| xbHTTPErrorHandler(oError,nil,.f.)}
xbIP2Decimal(cAddress) -> nAddress
Converts a dotted-decimal IP address into it's equivalent decimal format. The return value is a 32-bit unsigned integer.
Example:
nIP := xbIP2Decimal('216.19.71.75') // returns 3625142091
xbSaveToFile( cString, [cFile], [lAppend], [nMaxSize] ) -> lSuccess
Write the string cString to a file. If not specified, cFile defaults to xbSocket():ErrorLogFile.
If the file does not exist, it will be created. If lAppend is set to .T. (the default), then cString
will be appended to the end of the file. Otherwise the current file (if there is one) will be overwritten.
The function returns .T. if the data was written successfully.
The optional parameter nMaxSize can be used to specify the maximum size in bytes of the log file. When the file reaches this size, it will be renamed with a tilde "~" extension and a new file will be created. If not provided nMaxSize defaults to 1000000 bytes. xbSocketErrorText( [nErrorCode], [lisSSL] ) -> cErrorText When lisSSL is NIL or .F., return error description of WinSock error code nErrorCode. Otherwise, when lisSSL is .T., return error description of OpenSSL error code nErrorCode. If not supplied, nErrorCode defaults to the most recent error code produced in this thread. xbTcpWindowSize( [nSize] ) -> nTcpWindowSize Get or set the system's TCP window size parameter. The TCP window is the amount of unacknowledged data in flight between the sender and the receiver. Although TCP tries to optimize the transmit window to maximize throughput over the lifetime of a connection, the value returned by xbTcpWindowSize puts a hard limit on the window size.
The TCP window size is stored in the system registry under the following path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpWindowSize
The system's TCP window size registry value can be changed by setting nSize to the desired number of bytes.
The optimal window size for a given TCP connection can be determined by multiplying the network bandwidth by the
delay. For example a 1.5Mbps DSL connection with a round-trip delay of 200ms gives a window size of 37,500 bytes. Keep
in mind that this parameter cannot be changed at will. A system reboot is typically required for the change to become
effective. The window size should therefore be made large enough to accomodate the fastest networks with the slowest delay.
xbTimezoneOffset( [nMinutes] ) -> nTimezoneOffset
Get/set the difference between the local time and GMT as an integer representing the number of minutes. Unless
the local time is GMT, this function should be called at program start so that xbGMTDate() can return the
correct GMT date. If a parameter is not specified, the function returns the current timezone offset. When using
Xbase++ 1.7 or higher, the timezone offset will be automatically set on startup to the return value of
SetLocale(NLS_ITZBIAS).
xbUniqueFile( [cPath], [cPrefix], [cExt], [nAttr], [@nHandle] ) -> cFileName
Creates and returns a file name that is unique within the directory specified. The file name is returned including path
information. If an error occurs, the return value is a null string and the error code can be retrieved using FError().
Parameters:
cPath
Optional character string that specifies the directory in which the file will be created. If not provided, the
system temporary file directory (defined in the 'TEMP' environment variable) is used.
cPrefix
Optional character string to use as the file name prefix. If not specified, the file prefix will default to "~".
cExt
Optional character string to use as the file name extension. If not specified, the file extension will default to ".tmp".
nAttr
An integer numeric value which sets the access mode for the file. Various symbolic constants are defined in the
Xbase++ include file "Fileio.ch". For more information, consult the Xbase++ documentation for
FCREATE. This parameter is optional and defaults to FC_NORMAL:
nHandle
This is an optional output parameter. If provided, the reference operator "@" must be placed in front of the
argument nHandle. In this case, the newly created file will be left in an open state with the low-level file
handle returned in the memory variable nHandle. The file remains open for write access until the file handle
is passed to the Xbase++ function FClose().
xbWChar(cAnsiString) -> cUnicodeString
Convert a single-byte ANSI string to double-byte unicode.
xbWindowHandle( [nHandle] ) -> nWindowHandle
Get or set the application's default window handle. A specific window handle can be set by calling this function with
a numeric nHandle value. The return value is used as the parent window by certain Internet error dialogs.
xbAND( n1, n2 ) -> nResult
Returns the bitwise AND of the values provided by n1 and n2.
xbOR( n1, n2 ) -> nResult
Returns the bitwise OR of the values provided by n1 and n2.
xbXOR( n1, n2 ) -> nResult
Returns the bitwise XOR of the values provided by n1 and n2.
xbNOT( nVal ) -> nResult
Returns the bitwise complement of nVal.
xbSHL( nVal, [nCount] ) -> nResult
Returns the value of nVal, shifted left by nCount bits. As bits are shifted left, zero's are placed on
the right. If not specified, nCount defaults to 1.
xbSHR( nVal, [nCount] ) -> nResult
Returns the value of nVal, shifted right by nCount bits. As bits are shifted right, zero's are placed
on the left. If not specified, nCount defaults to 1.
xbHtonl( nULong ) -> nResult
Convert a 32-bit unsigned long integer from host byte order to network byte order (little-Endian to big-Endian).
xbHtons( nUShort ) -> nResult
Convert a 16-bit unsigned short integer from host byte order to network byte order (little-Endian to big-Endian).
xbNtohl( nULong ) -> nResult
Convert a 32-bit unsigned long integer from network byte order to host byte order (big-Endian to little-Endian).
xbNtohs( nUShort ) -> nResult
Convert a 16-bit unsigned short integer from network byte order to host byte order (big-Endian to little-Endian).
xbBase64Encode( cString, [lCRLF76] ) -> cBase64String Return cString in base64 encoded format. Base64 encoding coverts binary information from 8 bits per byte to 6 bits per byte. Information in 3-8bit bytes (24 bits) is converted into 4-6bit bytes (same 24 bits), resulting in a encoded string that is 1.333 times larger than the original.
The optional parameter lCRLF76 can be set to .T. in order to have the encoded output stream formatted in lines of 76 characters. The default for lCRLF76 is .F. xbBase64Decode( cBase64String ) -> cOriginalString Decodes a base64 encoded string into it's original form. xbCrypt( cInString, [nLen], [nSeed] ) -> cOutString Encrypt or decrypt a string. Parameters: cInString The string to be encrypted or decrypted. nLen Optional number of characters within cInString to process. nSeed Optional random number seed. If cInString is the encrypted string, then the same random number seed as was used to encrypt the string must be supplied to decrypt it.
Example:
cCrypt := xbCrypt("ABCD")
? xbCrypt(cCrypt) // -> "ABCD"
xbEscape( cString, [cAllowed] ) -> cEscapedString
Convert an input string cString into URL encoded format where reserved characters are replaced with
a percent sign followed by a hex number. For example, the space character is replaced with %20, a question
mark (?) is replaced with %27.
cAllowed is an optional string that can be used to supply the list of characters which will NOT be
translated. If not directly specified, cAllowed will default to the following:
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_.!~*'()
xbUnEscape( cString ) -> cOriginalString
Decodes a URL encoded string into it's original form.
xbSSLAvailable() -> lSuccess Indicates whether the OpenSSL library has been loaded. The function returns .T. when the OpenSSL library is loaded and ready for use. Possible reasons why the OpenSSL library cannot be loaded include:
xbSSLFreeErrorQueue() -> NIL
Destroy a thread's error queue. This method must be called at end of a thread that uses an xbSSLContext. Failure to
do this may result in memory leaks. The xbServer, xbSocketThread and xbHTTPThread classes already perform a proper
cleanup at thread termination. It is therefore not necessary to call this method when the xbSSLContext is used in
conjunction with one of these classes.
xbSSLGetErrorString( [nError] ) -> cError
Return a human-readable string representing the OpenSSL error code nError. The returned string will have the following format:
error:[error code]:[library name]:[function name]:[reason string]
Where error code is an 8 digit hexadecimal number, library name, function name and reason string are ASCII text.
If nError is not provided, it defaults to the return value of xbSSLGetLastError().
xbSSLGetLastError() -> nError
Returns the earliest error code from the thread's OpenSSL error queue and removes the entry. This function can be
called repeatedly until there are no more error codes to return.
xbXML2Array( cXMLDocument ) -> aXMLTree Parse an XML document into a hierarchical array of XML tags. The returned array contains subarrays of 4 elements each which may be accessed with the following define constants available in Xb2NET.CH. An empty array will be returned when the passed string is not a valid XML document.
XTAG_NAME - xml tag element name as string.
XTAG_ATTRIB - element attributes as string.
XTAG_CONTENT - tag contents; a string (tag value) or array containing subnodes (XTAG_TYPE = XTYPE_NODE)
XTAG_TYPE - numeric value indicating type of XTAG_CONTENT. The following values are possible:
XTYPE_NODE - a subnode
XTYPE_TEXT - a data value
Example:
TEXT INTO cString
<env:Envelope
xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/1999/XMLSchema">
<env:Body>
<ns:getQuote
xmlns:ns="urn:xmethods-delayed-quotes"
env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<symbol xsi:type="xsd:string">IBM</symbol>
</ns:getQuote>
</env:Body>
</env:Envelope>
ENDTEXT
aXMLTree := xbXML2Array(cString)
// aXMLTree will contain the following:
{{env:Envelope, xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance" xmlns:xsd="http://www.w3.org/1999/XMLSchema",
{{env:Body, ,
{{ns:getQuote, xmlns:ns="urn:xmethods-delayed-quotes" env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/",
{{symbol, xsi:type="xsd:string", IBM, 1}}, 0}}, 0}}, 0}}
xbXMLDateTime( [dDate], [cnTime] ) -> cXMLDate
Return a string representing the date and time with timezone offset in the following format:
yyyy-mm-ddThh:mm:ss.0000000-hh:mm, eg:
2004-12-05T23:33:38.0000000-05:00
Both parameters are optional if not specified the current date/time is used. cnTime can be a numeric as returned by SECONDS(), or a string as returned by TIME(). The timezone is based on the return value of xbTimezoneOffset(). xbXMLGetAttribute( cAttrib | aXMLNode, [cAttribName] ) -> cAttribValue | NIL Return attribute value for a given attribute item. The first parameter can be specified as a string representing the entire attribute value, or as a XML Node array. If cAttribName is NIL, then the entire attribute is returned. When aXMLNode contains no attributes, the function returns NIL, otherwise if cAttribName is not found, the function returns a null string.
Example:
// using aXMLTree from xbXML2Array example above...
? xbXMLGetAttribute( aXMLTree[1], "xsd" )
// returns: http://www.w3.org/1999/XMLSchema
? xbXMLGetAttribute('se:arrayType="xsd:int[3]" xsi:type="se:Array"', 'type' )
// returns: se:Array
xbXMLGetNode( aXMLTree, cName ) -> aChildNode | NIL
Scan aXMLTree for a node with the name cName and return the first node found with that name. Note,
the returned node may itself contain other subnodes. The XTAG_TYPE element will specify the type of content (see
above). If cNode cannot be found, the function returns NIL.
Example:
// using aXMLTree from xbXML2Array example above...
? xbXMLGetNode( aXMLTree, "getQuote" )
// returns the following array:
{ns:getQuote, xmlns:ns="urn:xmethods-delayed-quotes" env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/",
{{symbol, xsi:type="xsd:string", IBM, 1}}, 0}
These functions provide an interface to the free and open-source ZLib compression library written by Jean-Loup Gailly and Mark Adler. Technical information, source code and compiled versions of the library can be found on the ZLib homepage: http://www.zlib.net/. xbZCompress( cData, [nLevel], [@nError], [lRaw] ) -> cCompressedData | NIL Compress an input string using the 'deflate' compression method. The function will return NIL if an error occurred. Parameters: cData The input string to be compressed. nLevel Optional parameter specifying the compression level to use. Where 0 = no compression, 1 = minimum compression, maximum speed, and 9 = maximum compression, slowest speed. If not specified, the compression level defaults to 6. nError Optional parameter that must be passed by reference. On return, nError will contain one of the following numeric codes:
Z_OK - the input string was successfully compressed.
Z_MEM_ERROR - failed; insufficient memory.
Z_BUF_ERROR - failed; output buffer was too small.
Z_STREAM_ERROR - failed; the nLevel parameter is invalid.
lRaw
Optional logical parameter specifying whether to include a 2-byte ZLib header in the output cCompressedData
string. When set to .T. (the default), the ZLib signature will NOT be included.
xbZCompressFile( cFileIn, cFileOut, [nLevel], [cFileAttr] ) -> lSuccess
Compress a file using the 'deflate' compression method. The function will return .F. if an error occurs, and .T. if successful.
Parameters:
cFileIn
The name of a file to be compressed.
cFileOut
The name of an output file where the compressed version of cFileIn will be stored.
nLevel
Optional parameter specifying the compression level to use. Where 0 = no compression, 1 = minimum compression,
maximum speed, and 9 = maximum compression, slowest speed. If not specified, the compression level defaults to 6.
cFileAttr
An optional character string describing the attributes to be set for the output file. One or more of the following
characters can be specified. Example, "HR" indicates a hidden, read-only file:
H - Hidden
S - System
R - Read-only
A - Archive
N - Normal (the default)
xbZCRC32( [nCRC], cBuffer, [nLen] ) -> nCRC32
Calculate a running CRC (Cyclic Redundancy Check) value of an input buffer. nCRC is the previous CRC value,
which defaults to zero if not provided. cBuffer is a character string buffer that we wish to calculate a CRC
for, and nLen is the number of bytes within cBuffer to examine. nLen defaults to the length of
cBuffer if not directly specified.
Example:
// calculate CRC32 value for a file
cBuffer := Space(32768)
nFile := FOpen("xb2net.dll", FO_READ)
nCRC := 0
while (nBytes := FRead(nFile, @cBuffer, 32768)) > 0
nCRC := xbZCRC32(nCRC, cBuffer, nBytes)
end
FClose(nFile)
? "CRC32 value = ", nCRC
xbZError( nError ) -> cErrorString
Returns a character string corresponding to a ZLib error code nError.
xbZUnCompress( cCompressedData, nOriginalSize, [@nError], [lRaw] ) -> cOriginalData | NIL
Inflate an input string that was previously compressed using the 'deflate' compression method. The function will return NIL if an error occurred.
Parameters:
cCompressedData
The compressed string to be inflated.
nOriginalSize
The (exact) original size of the uncompressed data.
nError
Optional parameter that must be passed by reference. On return, nError will contain one of the following numeric codes:
Z_OK - the input string was successfully uncompressed.
Z_MEM_ERROR - failed; insufficient memory.
Z_BUF_ERROR - failed; output buffer was too small.
Z_DATA_ERROR - failed, the input buffer cCompressedData was corrupted.
lRaw
Optional logical parameter specifying whether the input string cCompressedData contains a 2-byte ZLib
header. Setting lRaw to .T. (the default), indicates that the input string does NOT contain a header.
xbZUnload() -> lSuccess
Unload the ZLIB.DLL library. Returns .T. if the DLL file was unloaded successfully. Note that the ZLIB.DLL file is
automatically loaded whenever a ZLIB function is executed.
xbZVersion() -> cVersion
Returns the ZLIB.DLL version number as a string.
:New([nAddrFamily], [nSocketType], [nProtocol], [oSSLContext]) -> self, or;
:New(oParent, [nHandle]) -> self
Creates a new instance of the xbSocket class and allocates system resources to bind the newly created socket
to a specific transport service provider. All parameters are optional.
Connection-oriented sockets such as SOCK_STREAM provide full-duplex connections, and must be in a connected state before any data can be sent or received on it. A connection to another socket is created with a :Connect call. Once connected, data can be transferred using :Send and :Recv calls. When a session has been completed, a :Close or :Destroy must be performed.
The communications protocols used to implement a reliable, connection-oriented socket ensure that data is not lost or duplicated. If data for which the peer protocol has buffer space cannot be successfully transmitted within a reasonable length of time, the connection is considered broken and subsequent calls will fail with the :ErrorCode set to WSAETIMEDOUT.
Connectionless, message-oriented sockets allow sending and receiving of datagrams to and from arbitrary peers. If such a socket is connected to a specific peer (see :Connect), datagrams can be sent/received only to/from this peer. Parameters: nAddrFamily An address family, define constant AF_*. Default is AF_INET. nSocketType The socket type. Winsock 1.1 only supports types SOCK_STREAM (the default) and SOCK_DGRAM.
SOCK_STREAM - Provides sequenced, reliable, two-way, connection-based byte streams with an out-of-band data transmission mechanism. Uses TCP for the Internet address family.
SOCK_DGRAM - Supports datagrams, which are connectionless, unreliable buffers of a fixed (typically small) maximum length. Uses UDP for the Internet address family. nProtocol A particular protocol to be used with the socket that is specific to the indicated address family. Default is IPPROTO_IP. Other values can be discovered by using the :GetProtoByName and :GetProtoByNumber methods. oSSLContext This parameter can be set to an instance of xbSSLContext to secure data transmission on this socket. Note that only connection-oriented (SOCK_STREAM) sockets can be secured. oParent A parent/child relation can be established between sockets by using this parameter. The new instance will inherit :AddrFamily, :SockType, :Protocol, :SSLContext, :Encode, :Decode and :onError properties from oParent. This is done implicitly when a connection is accepted by the :Accept method. nHandle The :Handle of an already open socket. If a handle is not specified, a brand new socket will be created with the same address family, socket type and protocol as the oParent socket. :DllLoad() -> lSuccess Load and initialize winsock dll. :DllUnload() -> lSuccess Close all sockets and unload winsock dll. :DllReset() -> lSuccess Close all sockets and reinitialize winsock dll. :ErrorText(nErrorCode, [lisSSL]) -> cErrorText When lisSSL is NIL or .F., return error description of WinSock error code nErrorCode. Otherwise, when lisSSL is .T., return error description of OpenSSL error code nErrorCode. :GetHostByAddr(nAddress, nType) -> aHostInfo | NIL Retrieves the host information corresponding to a network address. nAddress is a numeric IP address in network byte order, nType is the address family, eg. AF_INET. The method returns an array containing host information, or NIL on failure. The following array constants available in Xb2NET.CH provide access to the individual array elements:
HOSTENT_CNAME - character string representing the name of the host
HOSTENT_ALIAS - a one dimension array holding alternate names of the host. If none exist the array will be empty
HOSTENT_NTYPE - numeric value indicating the address family, eg. AF_INET
HOSTENT_NLEN - length, in bytes required to represent the network byte order addresses in HOSTENT_ADDR
HOSTENT_ADDR - a one dimensional array of numeric IP addresses for the host in network byte order
:GetHostByName(cHostName) -> aHostInfo | NIL
Retrieves the host information corresponding to a host name. cHostName is a character string representing
the name of the host (eg. "sqlexpress.net") for which to retrieve the information. The method returns an
array containing host information, or NIL on failure. The following array constants available in Xb2NET.CH
provide access to the individual array elements:
HOSTENT_CNAME - character string representing the name of the host
HOSTENT_ALIAS - a one dimension array holding alternate names of the host. If none exist the array will be empty
HOSTENT_NTYPE - numeric value indicating the address family, eg. AF_INET
HOSTENT_NLEN - length, in bytes required to represent the network byte order addresses in HOSTENT_ADDR
HOSTENT_ADDR - a one dimensional array of numeric IP addresses for the host in network byte order
:GetProtoByName(cProtocolName) -> aProtocolInfo | NIL
Retrieves protocol information corresponding to a protocol name. The method returns an array containing
protocol information, or NIL on failure. The following array constants available in Xb2NET.CH provide access
to the individual array elements:
PROTOENT_CNAME - character string representing the official name of the protocol.
PROTOENT_ALIAS - a one dimension array holding alternate names of the protocol. If none exist the array will be empty.
PROTOENT_NUMBER - a numeric protocol number, in host byte order.
:GetProtoByNumber(nProtocolNumber) -> aProtocolInfo | NIL
Retrieves protocol information corresponding to a protocol number. The method returns an array containing
protocol information, or NIL on failure. The following array constants available in Xb2NET.CH provide access
to the individual array elements:
PROTOENT_CNAME - character string representing the official name of the protocol.
PROTOENT_ALIAS - a one dimension array holding alternate names of the protocol. If none exist the array will be empty.
PROTOENT_NUMBER - a numeric protocol number, in host byte order.
:GetServByName(cServiceName, [cProtocolName]) -> aServiceInfo | NIL
Retrieves service information corresponding to a service name and protocol. cProtocolName is optional,
if not specified, the method returns the first service where the name matches cServiceName. The method
returns an array containing service information, or NIL on failure. The following array constants available
in Xb2NET.CH provide access to the individual array elements:
SERVENT_CNAME - character string representing the official name of the service.
SERVENT_ALIAS - a one dimension array holding alternate names of the service. If none exist the array will be empty.
SERVENT_NPORT - a numeric port number at which the service can be contacted.
SERVENT_CPROT - the name of the protocol to use when contacting the service.
:GetServByPort(nPort, [cProtocolName]) -> aServiceInfo | NIL
Retrieves service information corresponding to a port and protocol. cProtocolName is optional, if not
specified, the method returns the first service where the port number matches nPort. The method
returns an array containing service information, or NIL on failure. The following array constants available
in Xb2NET.CH provide access to the individual array elements:
SERVENT_CNAME - character string representing the official name of the service.
SERVENT_ALIAS - a one dimension array holding alternate names of the service. If none exist the array will be empty.
SERVENT_NPORT - a numeric port number at which the service can be contacted.
SERVENT_CPROT - the name of the protocol to use when contacting the service.
:InetAddr(cAddress) -> nAddress
Converts a dotted-decimal IP address (eg. '127.0.0.1') to a numeric Internet address in network byte order
:InetNtoA(nAddress) -> cAddress
Converts a numeric Internet network byte order address into it's human readable dotted-decimal string format, eg. '127.0.0.1'
:Copyright
readonly/character
Returns Xb2.NET library copyright information
:DisplayErrors
exported/logical
Enable/disable console display of winsock error and warning messages. When set to .T., a console dialog box
will be displayed whenever a winsock error occurs. The default setting is .F.. The most recent winsock error
is saved in the :ErrorCode ivar.
:DllDescription
readonly/character
Description of the Windows Sockets implementation.
:DllStatus
readonly/character
Relevant status or configuration information as returned by winsock.
:DllVersion
readonly/character
The version of the Windows Sockets specification used on the local machine.
:ErrorLogFile
exported/character
The name of the file where errors are logged. Default is XB2ERROR.LOG. This property is used by the
xbErrorLog function.
:LocalName
readonly/character
Standard host name of the local machine.
:Version
readonly/character
Returns Xb2.NET library version number as a string.
Life Cycle :Open([nAddrFamily], [nSocketType], [nProtocol]) -> lSuccess Allocates system resources and causes the socket to be bound to a specific transport service provider. Technically this is equivalent to calling :New() except that a new class instance is not created. For additional information on parameters, see :New(). :Bind([xLocalAddr], [nPort]) -> lSuccess Associate a local address with a socket. This method is used to bind to either connection-oriented (stream) or connectionless (datagram) sockets before subsequent calls to the :Connect or :Listen methods. When a socket is instantiated or opened using :Open, it is associated with an address family only. In order for the socket to be able to communicate with a remote process it should be bound to a local address and port. Parameters: xLocalAddr The local address can be specified either as a numeric address in network byte order, or as an IP address in form of a dotted octet string (ex. 127.0.0.1). If an application does not care what local address is assigned, specify the constant value INADDR_ANY (the default). This allows the underlying service provider to use any appropriate network address, potentially simplifying application programming in the presence of multihomed hosts (hosts that have more than one network interface and address). nPort This is the numeric port number on the local computer to bind the socket to. The default is zero and this allows the underlying service provider to assign a unique port to the application with a value between 1024 and 5000. Binding to a specific port number other than port 0 is discouraged for client applications, since there is a danger of conflicting with another socket already using that port number. :Connect(xRemoteAddr, nPort) -> lSuccess This method is used to establish a connection to a specified destination. If the socket is unbound, unique values are assigned to the local association by the system, and the socket is marked as bound.
Connection-oriented sockets (eg. SOCK_STREAM), must be in a connected state before data can be transmitted using :Send/:Recv. Any attempt to re-connect an active connection will fail with the :ErrorCode WSAEISCONN.
For a connectionless socket (eg. SOCK_DGRAM), the operation performed by :Connect is merely to establish a default destination address that will be used on subsequent :Send and :Recv calls. Any datagrams received from an address other than the destination address specified will be discarded. If the xRemoteAddr parameter is specified as zero, the socket will be "disconnected". The default destination can be changed by simply calling connect again, even if the socket is already connected. Any datagrams queued for receipt are discarded if xRemoteAddr or nPort are different from the previous connect.
Any valid xRemoteAddr and nPort can be specified for connectionless sockets, including a broadcast address. However, to connect to a broadcast address, :Broadcast(.t.) must be set first. Otherwise, :Connect will fail with the :ErrorCode WSAEACCES. Parameters: xRemoteAddr The remote address can be specified either as a numeric address in network byte order, or as an IP address in form of a dotted octet string (ex. 127.0.0.1). nPort This is the numeric port number on the remote computer to connect to. :SSLConnect([oSSLContext]) -> lSuccess Initiate a SSL/TLS handshake with a connected server. The socket must be of type SOCK_STREAM and it must already be in a connected state when this method is called.
oSSLContext is an optional parameter than can be set to an instance of the xbSSLContext class. This is only necessary if specific SSL/TLS properties need to be set, such as a client certificate, CA lists, cypher suites, etc.
The method will return .T. if an SSL/TLS connection has been successfully established with the peer. Otherwise, the method returns .F. :Listen([nBacklog]) -> lSuccess Place a socket in a state where it is listening for incoming connections. This method is typically used by servers that can have more than one connection request at a time. If a connection request arrives and the queue is full, the client will receive an error with an indication of WSAECONNREFUSED.
nBacklog is an optional parameter that specifies the maximum length of the queue of pending connections. If this value is SOMAXCONN (the default), then the underlying service provider responsible for this socket will set the backlog to a maximum "reasonable" value. There is no standard provision to find out the actual backlog value.
Subsequent calls to :Listen will update the current backlog for the listening socket. If there are more pending connections than the new backlog value, the excess pending connections will be reset and dropped. :Accept([oSocketClass]) -> oClientSocket | NIL This method is used by a server process for accepting incoming connections. The method extracts the first connection in the queue of pending connections and then creates a new socket object that is bound to the extracted connection. The newly created socket inherits most of it's properties from the parent (this socket) and is the socket that will handle the actual communication with the remote process.
The optional parameter oSocketClass can be used to provide a reference to the class function from which the new socket object will be instantiated. If oSocketClass is NIL, then the client socket will be created based on one of the following conditions: (1) if the parent (this socket) is derived from either xbServer or xbHTTPServer, the client socket will be instantiated from the class object referenced by the server's :WorkerClass property (usually xbSocketThread or xbHTTPThread), (2) otherwise the new socket will be instantiated from xbSocket.
If the socket is marked as blocking (see :SetBlockingMode) and there are no pending connections on the queue, then the :Accept method will block the calling routine until a connection is present. If the socket is marked nonblocking and no pending connections are present on the queue, :Accept returns NIL. After the successful completion of :Accept, the method returns a new socket object. The original socket remains open and listens for new connection requests. :Recv([nBytes], [nFlag], [cBuffer], [nDelayTime]) -> cReceived | NIL Read incoming data. Calling :Recv on a connection-oriented socket (eg. SOCK_STREAM), will return as much information as is currently available; up to nBytes. If the socket has been configured for in-line reception of out-of-band data (see :OOBInLine) and out-of-band data is available; only out-of-band data will be returned. The application can use :CatMark to determine whether any more out-of-band data remains to be read.
For message-oriented or connectionless sockets (eg. SOCK_DGRAM), data is extracted from the first enqueued datagram (message); up to nBytes. If the datagram or message is larger than nBytes, the first part of the datagram is returned, and :ErrorCode will be set to WSAEMSGSIZE. For unreliable protocols (eg. UDP) the excess data is lost; for reliable protocols, the data is retained by the service provider until it is successfully read by calling :Recv with a large enough buffer. If the socket is not connected, the network address of the peer that sent the data will be copied into the :RemoteAddr and :RemotePort ivar.
If there is no incoming data available and the socket is in blocking mode (see :SetBlockingMode), then
:Recv will block the calling routine and wait for data to arrive. If the socket is nonblocking and the
input queue is empty, :Recv returns a zero length string and :ErrorCode is set to
WSAEWOULDBLOCK. After successfully reading data from the input queue :Recv returns a string containing
the data read. If an error occurs, other than the ones specified above, the method returns NIL. The number of
bytes read is saved in the :BytesReceived ivar and a cumulative total in :RecvCount.
Parameters:
nBytes
The number of bytes to read from the input queue. If not specified, nBytes will default to 1460 bytes or
if supplied; the size of cBuffer.
nFlag
Specifies the way data will be read from the input queue. The following options defined in Xb2NET.CH are available:
MSG_NORMAL - Read incoming data and remove it from the input queue (this is the default).
MSG_PEEK - Peek at the incoming data but do not remove it from the input queue.
MSG_OOB - Process out-of-band data.
cBuffer
An optional character string buffer that will be used to receive data into. If supplied, it must be passed by
reference and it's size must be greater than or equal to nBytes. If nBytes is NIL, then the method
will continue reading until cBuffer is full. If :Recv is called continuously (eg. in a loop), then
it's good programming practice to receive into a static buffer since it results in more efficient memory usage.
nDelayTime
Specifies an optional delay period in milliseconds to hold-off reading from the input queue until nBytes
is available to be read. This can be useful when the peer is transmitting large amounts of data over a slow
network since it will result in more efficient buffer and memory usage on the host machine.
The delay will persist as long as data is being received and the number of bytes in the receive buffer is less than nBytes. The method checks the receive buffer every 20 ms, if no additional data is received within that time, it will read the data received so far and return to calling routine even if the dalay time has not yet expired. This parameter is only applicable on a connection-oriented socket. :RecvFile( xFile, [nBytesToRecv], [nBytesPerRecv] ) -> nBytesReceived | SOCKET_ERROR Read incoming data and save it into a file. For additional information on how data is read from the input queue, see :Recv above. Parameters: xFile The file where received data is saved can be specified as either a numeric handle as returned by FOpen() or FCreate(), or as a character string denoting the file name and path. NOTE: If a file handle is provided, then received data will be saved starting at the current file pointer offset. On return, the file will be left open and the file pointer will be positioned on the last byte written. If a file name is specified instead of a numeric handle, then the file will be closed. nBytesToRecv Number of bytes to read. The method completes when it has read the specified number of bytes, or when an error occurs, whichever occurs first. Set nBytesToRecv to zero or NIL in order to continue reading into file until socket is disconnected. nBytesPerRecv Data is read from the input queue in discrete blocks. This parameter specifies the number of bytes of data read per block. Set nBytesPerRecv to zero or NIL to select the default read size. This parameter is useful for message protocols that have limitations on the size of individual read requests. :RecvLine([cEOLMarker], [nMaxBytes]) -> cReceived | NIL Read incoming data on a connection-oriented socket (eg. SOCK_STREAM) until cEOLMarker is reached or if specified; nMaxBytes have been read. If cEOLMarker is not supplied it defaults to CR+LF (Chr(13) + Chr(10)). See :Recv for additional information. :Send(cBuffer, [nFlag], [xToAddr], [nToPort], [nBytesToSend]) -> nBytesSent | SOCKET_ERROR Send data to a specific destination or a connected peer. If the socket is unbound, unique values are assigned to the local association by the system, and the socket is marked as bound. The successful completion of a :Send does not indicate that the data was successfully delivered.
For message-oriented sockets, care must be taken not to exceed the maximum packet size of the underlying provider, (see :MaxMessageSize). If the data is too long to pass atomically through the underlying protocol, :ErrorCode will be set to WSAEMSGSIZE, and no data is transmitted.
If no buffer space is available within the transport system to hold the data to be transmitted, :Send
will block unless the socket has been placed in a nonblocking mode. On nonblocking, stream oriented sockets,
the number of bytes written can be between 1 and the requested length, depending on buffer availability on
both the client and server systems.
Parameters:
cBuffer
This is the buffer containing the data to be transmitted.
nFlag
Specifies the way in which the call is made. The following options defined in Xb2NET.CH are available:
MSG_NORMAL - Read incoming data and remove it from the input queue (this is the default).
MSG_DONTROUTE - Specifies that the data should not be subject to routing.
MSG_OOB - Send out-of-band data (SOCK_STREAM only).
xToAddr
This parameter is only valid when used with connectionless, message-oriented sockets. It is ignored if
:SockType is SOCK_STREAM, otherwise xToAddr can be any valid address in the socket's address
family, including a broadcast address. However, to send to a broadcast address, :Broadcast(.t.)
must be set first. Otherwise, :Send will fail with the :ErrorCode WSAEACCES. For TCP/IP, an
application can send to any multicast address without becoming a group member. If a message-oriented
socket has been previously connected to a specific address (using :Connect), specifying
xToAddr will override the default destination address for this datagram only. The address can be
specified either as a numeric address in network byte order, or as an IP address in form of a dotted octet
string (ex. 127.0.0.1). Default is INADDR_BROADCAST.
nToPort
This parameter is only valid when used with connectionless, message-oriented sockets. It is ignored if
:SockType is SOCK_STREAM, otherwise it specifies the numeric port number on the remote computer to
send to. Default is zero.
nBytesToSend
The number of bytes to send. If the parameter is NIL or not provided, the default is to send the entire contents of cBuffer.
:SendFile(xFile, [nBytesToSend], [nBytesPerSend]) -> nBytesSent | SOCKET_ERROR
Transmit file data over a connected socket. The method returns an integer numeric value indicating the
number of bytes transmitted, or SOCKET_ERROR if an error occurred. NOTE: The successful completion
of a :SendFile does not necessarily indicate that the data was successfully delivered to the
remote peer.
Parameters:
xFile
The file to be transmitted can be specified as either a numeric handle as returned by FOpen() or FCreate(), or
as a character string denoting the file name and path. NOTE: If a file handle is specified, then data will be
transmitted beginning at the current file pointer offset. To transmit the entire file make sure that the file
pointer is set to the beginning of the file. If a numeric file handle is provided, then it is the
responsibility of the calling routine to close the file once the method returns.
nBytesToSend
Number of file bytes to transmit. The method completes when it has sent the specified number of bytes, or
when an error occurs, whichever occurs first. Set nBytesToSend to zero or NIL in order to transmit
the entire file.
nBytesPerSend
The file contents are transmitted in discrete blocks of data. This parameter specifies the number of bytes
of data sent per block. Set nBytesPerSend to zero or NIL to select the default send size. This
parameter is useful for message protocols that have limitations on the size of individual send requests.
:Shutdown([nHow], [lShutdownClients]) -> lSuccess
This method is used on all types of sockets to disable reception and/or transmission of data. Note that
:Shutdown does not close the socket. A socket can only be closed by executing the :Close or
:Destroy methods. The method returns .T. when the shut down operation is successful, otherwise .F. is
returned.
If the nHow parameter is set to SD_SEND, subsequent calls to :Send will be disallowed. If it is set to SD_RECEIVE (the default), subsequent calls to :Recv are disallowed. If it is set to SD_BOTH then both sends and receives are disabled.
If the socket is in a listening state and there are connected clients, the client sockets can be shut down by specifying .T. for lShutdownClients default is .F. :SSLShutdown() -> self Send an SSL/TLS shutdown request to the remote peer and wait for an acknowledgement that the peer has shut down. If there is no SSL connection open on the socket, then the method will return immediately. :Close([lCloseClients]) -> lSuccess Closes socket and releases allocated system resources. Any pending blocking, asynchronous calls issued by any thread in this process are canceled without posting any notification messages. If the socket is in a listening state and there are connected clients, the client sockets can also be closed by specifying .T. for lCloseClients, default is .F. The semantics of :Close are affected by the :LingerTimeout option, see :LingerTimeout for additional information. A socket that has been closed can later be reopened by using the :Open method. :Destroy([lDestroyClients]) -> lSuccess This method will first execute a :Close and if successful, the class instance will be dereferenced from the class object list. If the socket is in a listening state and there are connected clients, the client socket objects can also be destroyed by specifying .T. for lDestroyClients, default is .F. Configuration :Broadcast([lSet]) -> lSet Enable/disable transmission of broadcast messages on the socket. When lSet is not specified, the method will return the current setting. Default is .F. :Debug([lSet]) -> lSet Enable/disable recording of debugging information. When lSet is not specified, the method will return the current setting. The mechanism for generating the debug information and the form it takes are dependant on the winsock service provider and are beyond the scope of this manual. Default is .F. :KeepAlive([lSet]) -> lSet Enable/disable use of "keep-alive" packets on TCP connections. When lSet is not specified, the method will return the current setting. Default is .F. :LingerTimeout([nSec]) -> nSetting This method controls the action taken when unsent data is queued on a socket and a :Close or :Destroy is performed. The following types of behavior can be obtained:
nSec is specified as a negative value: Graceful shutdown, immediate return - allowing the shutdown sequence to complete in the background. Although this is the default behavior, the application has no way of knowing when (or whether) the graceful shutdown sequence actually completes.
nSec is specified as zero: Abortive shutdown sequence, immediate return from :Close
nSec is specified as a positive value: Graceful shutdown, delaying return until either shutdown sequence completes or the specified time interval elapses. If the time interval expires before the graceful shutdown sequence completes, an abortive shutdown sequence occurs, and :Close returns.
When nSec is not specified, the method will return the current setting. :OOBInLine([lSet]) -> lSet Enable/disable the reception of out-of-band data in the normal data stream. When lSet is not specified, the method will return the current setting. Default is .F. :RecvBufferSize([nSize]) -> nBytes Get/set buffer size for receives. When nSize is not specified, the method will return the current size of the receive buffer in bytes. :RecvTimeout([nMilliSec]) -> nTimeout Get/set maximum number of millisecs to wait when receiving data from a remote connection (may not work with all stack implementations). This option can be set on any type of socket in any state. The default value is zero, which refers to an infinite timeout. Any other setting is the timeout, in milliseconds. It is valid to set the timeout to any value, but values less than 500 milliseconds (half a second) are interpreted to be 500 milliseconds. When nMilliSec is not specified, the method will return the current setting. :ReuseAddr([lSet]) -> lSet By default, a socket cannot be bound to a local address that is already in use. Sometimes, however, it can be necessary to reuse an address in this way. Because every connection is uniquely identified by the combination of local and remote addresses, there is no problem with having two sockets bound to the same local address as long as the remote addresses are different. In order to allow the socket to be bound to an address that is already in use, the application should call this method by specifying lSet as .T. before issuing a :Bind call. Setting or resetting the option after the :Bind has no effect on this or any other socket. When lSet is not specified, the method will return the current setting. Default is .F. :Route([lSet]) -> lSet Enable/disable routing; when disabled packets are sent directly to interface. When lSet is not specified, the method will return the current setting. Default is .T. (enable routing). :SendBufferSize([nSize]) -> nBytes Get/set buffer size for sends. When nSize is not specified, the method will return the current size of the send buffer in bytes. :SendTimeout([nMilliSec]) -> nTimeout Get/set maximum number of millisecs to wait when sending data to a remote connection (may not work with all stack implementations). This option can be set on any type of socket in any state. The default value is zero, which refers to an infinite timeout. Any other setting is the timeout, in milliseconds. It is valid to set the timeout to any value, but values less than 500 milliseconds (half a second) are interpreted to be 500 milliseconds. When nMilliSec is not specified, the method will return the current setting. :SetBlockingMode([lSet]) -> lSet Enable/disable blocking mode on the socket. When enabled (which is the default), the process executing :Accept or sending/receiving data will wait for the operation to complete. If not specified lSet defaults to .T. :SetCallBack([xCallBack]) -> self Register an object or codeblock to receive callback events. If a callback has already been registered, it can be cancelled by setting xCallBack to NIL.
When xCallBack is provided as an object, the object must be inherited from the Xbase++ XbpPartHandler class. In this case, the xbSocket class will place events of type xbeP_xbSocket into the Xbase++ event queue. These events can be read (asynchronously) from the event queue by using the standard Xbase++ function AppEvent(). For an example showing how to define asynchronous callbacks, please see: xbFTPClient:SetCallBack.
When xCallBack is provided as a codeblock, the user codeblock will be executed (synchronously) whenever an event occurs within the xbSocket instance.
Two message parameters are provided to the AppEvent() function / user codeblock. The first parameter will be an integer numeric status code defined in Xb2NET.CH with the prefix SOCK_ST_*, the second parameter will contain a reference to the socket object.
Example (synchronous callback):
oSock:SetCallBack({|a,b|DisplayStatus(a,b)}) // codeblock executes synchronously
PROCEDURE DisplayStatus(nStatus, x)
Static oXbp
Local oWindow
// create status CRT window if it does not exist
if oXbp == nil
oXbp := XbpCrt():new(,,{372,165},15,33,"STATUS")
oXbp:autoFocus := .F.
oXbp:create()
endif
// display status info in separate CRT window
oWindow := SetAppWindow(oXbp)
if valtype(x) == "O" .and. x:isDerivedFrom("xbSocket")
? nStatus, x:SendCount, x:RecvCount
else
? nStatus, x
endif
DispOutAt(0,0,"StatusCode SendCount RecvCount", "gr+,w")
SetAppWindow(oWindow)
Return
:SetSSLContext([oSSLContext]) -> self
Attach an xbSSLContext object, oSSLContext to this socket in order to secure
communications. The socket must be of type SOCK_STREAM and it must not be connected or in a listening state when
the xbSSLContext object is attached. If oSSLContext is NIL or no parameter is supplied, then the present
SSL/TLS connection (if there is one) will be shut down and it's corresponding xbSSLContext will be detached from
this socket.
:TCPNoDelay([lSet]) -> lSet
Enable/disable use of Nagle algorithm for sends. The Nagle algorithm is disabled when lSet is .T. (and vice
versa). The process involves buffering :Send data when there is unacknowledged data already "in flight" or
buffering :Send data until a full-size packet can be sent. For most application protocols the Nagle Algorithm
can deliver significant performance enhancements. However, in some cases this algorithm can impede performance,
and :TCPNoDelay can be used to turn it off. These are applications where many small messages are sent, and
the time delays between the messages are maintained. When lSet is NIL, the method returns the current setting.
Status
:ErrorMessage() -> cErrorText
Return error description of most recent WinSock error.
:CatMark() -> lNoOOBDataWaiting
Check if out-of-band data is waiting to be read. This applies only to a stream oriented socket (eg.
SOCK_STREAM) that has been configured for in-line reception of out-of-band data; see :OOBInLine. If no
out-of-band data is waiting to be read, the operation returns .T. Otherwise, it returns .F., and the next
:Recv or :RecvLine performed on the socket will retrieve some or all of the data preceding the
"mark". The application should use :CatMark to determine whether any data remains.
:GetReadCount() -> nBytesAvailable
Use to determine the amount of data pending in the network's input buffer that can be read from the socket.
If the socket is stream oriented (eg. SOCK_STREAM), this method returns the amount of data that can be read
in a single call to the :Recv method; this might not be the same as the total amount of data queued on
the socket. If the socket message oriented (ex. SOCK_DGRAM), this method returns the size of the first
datagram (message) queued on the socket.
:isListening() -> lListening
Check if socket is in listening mode.
:isConnected() -> lConnected
Check if a connected socket is still alive.
:isSecure() -> lSecureConnecton
Check if there is a secure SSL/TLS connection open.
:MaxMessageSize() -> nBytes
Maximum size of a message for message-oriented socket types (eg., SOCK_DGRAM). Has no meaning for stream
oriented sockets.
:RemoteName() -> cHostName | NIL
Return host name of remote machine or NIL if the remote host name cannot be resolved.
:UpTime() -> {nDays, nHrs, nMin, nSec}
Returns a one dimensional array specifying amount of time socket has been open. The following array constants
available in Xb2NET.CH provide access to the individual array elements:
UPTIME_DAY - number of days
UPTIME_HRS - number of hours
UPTIME_MIN - number of minutes
UPTIME_SEC - number of seconds
Child/Parent Relation
:AddClient(oSocket) -> self
Create a parent/child relation between this socket (the parent) and oSocket (the child). A list of
all client sockets is available in the :ClientList ivar.
:DelClient(oSocket) -> self
Remove parent/child relation between this socket and oSocket. A list of all client sockets is
available in the :ClientList ivar.
:SetParent([oParent]) -> self
Create or remove a parent/child relation between this socket (the child) and oParent (the parent). If
oParent is not specified, the link is removed, otherwise a link is created. A reference to the parent
socket is stored in the :Parent ivar.
:Handle
readonly/numeric
Numeric socket descriptor as used by winsock.
:SSLHandle
readonly/numeric
Numeric descriptor of SSL object as used by OpenSSL.
:AddrFamily
readonly/numeric
The socket's address family. #define constants: AF_*
:SockType
readonly/numeric
The socket type. #define constants: SOCK_STREAM, SOCK_DGRAM, SOCK_RAW, SOCK_RDM, SOCK_SEQPACKET
:Protocol
readonly/numeric
The protocol used. #define constants: IPPROTO_*
:LocalAddr
readonly/numeric
The numeric IP address of the local machine in network byte order that the socket is bound to.
:LocalPort
readonly/numeric
The numeric port number on the local machine that the socket is bound to.
:RemoteAddr
readonly/numeric
The numeric IP address of the remote machine in network byte order that the socket is connected to.
:RemotePort
readonly/numeric
The numeric port number on the remote machine that the socket is connected to.
:BytesReceived
readonly/numeric
Number of bytes received by last :Recv or :RecvLine call.
:BytesSent
readonly/numeric
Number of bytes transmitted by last :Send call.
:RecvCount
readonly/numeric
A cumulative total of number of bytes received on this socket since it was opened.
:SendCount
readonly/numeric
A cumulative total of number of bytes sent on this socket since it was opened.
:ErrorCode
exported/numeric
Most recent result code returned by winsock.
:onError
exported/codeblock
Provides the ability to optionally specify a codeblock that will be evaluated when a winsock error occurs.
When evaluated three parameters are passed to the codeblock (1) a reference to socket object responsible for
the error, (2) the OpenSSL or Winsock error code number, and (3) a logical indicating if the error
originated from the OpenSSL library (.T.) or from WinSock (.F.). Example:
oSocket:onError := {|oOwner,nErrCode,isSSL| xbErrorLog(oOwner,nErrCode,isSSL)}
:isEncoded
exported/logical
Provides the ability to automatically encode and decode data transmitted on the socket. When set to .T.,
all inbound data will be decoded (see :Decode) and all outbound data will be encoded (see
:Encode). This is quite a powerful feature since it means that data can be transparently "massaged"
before it is passed on. For example, using the following codeblocks, any datatype can be sent and received
between Xbase++ applications. Send an array, receive an array; send a codeblock, receive a codeblock...
you can imagine the possibilities.
oSocket:isEncoded := .T.
oSocket:Encode := {|xVal| Var2Bin(xVal)}
oSocket:Decode := {|cBuffer,nBytes| Bin2Var(Left(cBuffer,nBytes))}
:Encode
exported/codeblock
Optional codeblock that is automatically evaluated to encode outbound data when :isEncoded is .T. If
no user codeblock is supplied but :isEncoded is .T. a default built-in encryption algorithm will be
used. When evaluated two parameters are passed to the codeblock (1) a reference to the value being
transmitted, (which may be any data type), and (2) if the value to be transmitted is a string, this parameter
will contain the length of the string, otherwise it will be -1. See :isEncoded for more information.
:Decode
exported/codeblock
Optional codeblock that is automatically evaluated to decode inbound data when :isEncoded is .T. If
no user codeblock is supplied but :isEncoded is .T. a default built-in decryption algorithm will be
used. When evaluated two parameters are passed to the codeblock (1) a text buffer of the data received, and
(2) the number of bytes received. See :isEncoded for more information.
:Parent
readonly/object
Reference to parent socket or NIL if this socket has no parent.
:ClientList
readonly/array
A one dimensional array listing all active client sockets either created through this socket's :Accept
method or :AddClient method.
:DateStarted
readonly/date
Date socket opened.
:TimeStarted
readonly/numeric
Time socket opened (seconds after midnight).
:ThreadID
readonly/numeric
Xbase++ thread ID number where socket was created.
:SSLContext
readonly/object
Reference to the xbSSLContext instance, or NIL if no SSL context has been assigned.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
inherited from xbSocket and Thread
This class implements a generic socket listener that spawns an xbSocketThread when a client connection is accepted.
:New([xLocalAddr], [nPort], [oSSLContext], [cName]) -> self Creates a new instance of the xbServer class and allocates system resources to bind the newly created socket to a specific transport service provider. The xbServer class is inherited from xbSocket and Thread (part of Xbase++). An instance of this class will therefore have access to all methods and properties of it's superclasses. For information on the Thread class, please consult your Xbase++ documentation. All parameters are optional. Parameters: xLocalAddr The local address can be specified either as a numeric address in network byte order, or as an IP address in form of a dotted octet string (ex. 127.0.0.1). If an application does not care what local address is assigned, specify the constant value INADDR_ANY (the default). This allows the underlying service provider to use any appropriate network address. nPort This is the numeric port number on the local computer to bind the socket to. If not supplied, the default is 23 (or 992 when using an xbSSLContext) which are the standard port numbers for Telnet and TelnetS respectfully. oSSLContext In order to secure data transmission and possibly authenticate clients, an instance of xbSSLContext can be passed using this parameter. cName Optional descriptive name to associate with the thread instance. See Xbase++ documentation Thread:Name.
:ActiveConnections() -> nConnectionsOpen Returns the total number of connections currently open. :SetBacklog([nBacklog]) -> nBacklog Get/set the maximum length of the queue of pending connections. If this value is SOMAXCONN (the default), then the underlying service provider responsible for this socket will set the backlog to a maximum "reasonable" value. There is no standard provision to find out the actual backlog value however if nBacklog is not specified, the method will return the current backlog setting (which may not necessarily be the actual backlog value set by the service provider).
If the server is running and the socket is in a listening state, calls to :SetBacklog will update the current backlog for the socket. If there are more pending connections than the new backlog value, the excess pending connections will be reset and dropped. :Start() -> lSuccess Start running the server in its own thread. If the server thread is started successfully, the method returns .T., otherwise it returns .F. Once started, the server will begin listening for incoming connections on the address and port specified when the xbServer object was instantiated. A new xbSocketThread object will be instantiated and bound to each accepted connection. It is the xbSocketThread object that is responsible for handling the actual communications with the client.
The server will continue running in it's own thread and listening for incoming connections until it is terminated by calling the :Stop method. Once the server has stopped, it can be restarted by calling :Start. As long as the server thread is active, repeated calls to :Start are ignored. :Stop([nTimeOut]) -> lSuccess Close server socket and signal server plus all connected clients to terminate. nTimeOut is an optional parameter specifying the maximum amount of time, in 1/100ths of a second, to wait for the xbServer thread (including all connected clients) to terminate. The default value of zero causes the current thread (where :Stop was called) to wait indefinitely until the xbServer thread and all connected clients have terminated. The method returns .F. if the server could not be terminated within the specified time interval, otherwise it returns .T.
Status
:ConnectCount
exported/numeric
Total number of connections accepted since server started. This is not the same as :ActiveConnections.
:ThreadID
readonly/numeric
Numeric ID of thread.
Configuration
:MaxConnections
exported/numeric | NIL
Maximum allowable number of concurrent client connections. A value of NIL (the default) does not impose a
limit on the number of concurrent client connections. See :onMaxConnect for additional information.
:SleepTime
exported/numeric
Amount of time in 1/100ths of a second to idle the xbServer thread after accepting a new connection.
:WorkerClass
exported/reference to class function
This instance variable provides a reference to a client socket handler class function. By default
:WorkerClass contains a reference to the xbSocketThread class function, however it can be used
to define a custom client socket handler to be used instead of xbSocketThread. When instantiated, the
init method of the worker class will receive two parameters: (1) a reference to the parent server object, and
(2) a numeric handle of the newly created socket. If a custom class is used, it should be derived either from
the xbSocket and Thread classes or from the xbSocketThread class.
Example:
oServer:WorkerClass := MyClientHandler()
CLASS MyClientHandler FROM xbSocketThread
EXPORTED:
INLINE METHOD Init(oParent, nHandle)
::xbSocketThread:init(oParent, nHandle)
// add your custom init code here
Return self
// The :Execute method is where all the work is done, add your custom code here
INLINE METHOD Execute()
Local cRecv := ::Recv()
if ::BytesReceived > 0
::Send( cRecv ) // just echo back whatever we receive
endif
Return self
ENDCLASS
Event Handling
:atEnd
exported/character | codeblock | NIL
Can be used to provide an optional code block or a character string containing the name of a globally visible
function that will be executed before the thread terminates. This property will be inherited by worker threads.
:onConnect
exported/codeblock | NIL
This is the codeblock that will be executed when a client connection is accepted. If :onConnect is
NIL, then the server will simply echo back to the client all received data (this is the default behavior).
For the server to do anything useful, a codeblock must be attached to this ivar. The purpose of this
codeblock is to receive the client request, process as required and send back a response. The connected socket
can be kept open as long as required or until the client disconnects.
It is important to note that the code encapsulated by the codeblock will be executed in a new xbSocketThread. This thread remains active as long as the socket connection is open. It may be terminated by closing the socket connection (from either the server or client sides) and exiting the procedure. The client socket will be automatically shut down and closed just before the thread terminates.
Example:
oServer:onConnect := {||ServiceClient()}
Procedure ServiceClient()
Local cRecv, cSend
Local oClient := ThreadObject()
Local cTempFile := "~" + NTrim(oClient:Handle) + ".tmp"
while (cRecv := oClient:RecvLine()) != NIL
cSend := cRecv
cRecv := StrTran(StrTran(cRecv,chr(10),""),chr(13),"")
RunShell( "/C " + cRecv + " > " + cTempFile,,.f.,.t. )
cSend += MemoRead(cTempFile)
FErase(cTempFile)
if oClient:Send( cSend ) < 0
exit
endif
end
Return
:onMaxConnect
exported/character | codeblock | NIL
The :onMaxConnect ivar determines what happens when :ActiveConnections reaches :MaxConnections. The following options are possible:
NIL - do not accept any more connections until an existing client connection is closed.
STRING - accept new connection, receive request, send string contained in :onMaxConnect to client and immediately close connection.
CODEBLOCK - accept new connection, create new xbSocketThread object and execute codeblock contained in :onMaxConnect within this new thread.
Example:
oServer:MaxConnections := 50
oServer:onMaxConnect := "Too many connections, please try later..."
// or
oServer:onMaxConnect := {||SendBusy()}
Procedure SendBusy()
Local oThread := ThreadObject()
oThread:Recv()
if oThread:BytesReceived > 0
oThread:Send( "Too many connections, please try later...")
endif
Return
inherited from xbServer
This class implements an HTTP 1.1 listener that spawns an xbHTTPThread when a client connection is accepted.
:New([xLocalAddr], [nPort], [oSSLContext], [cName]) -> self Creates a new instance of the xbHTTPServer class and allocates system resources to bind the newly created socket to a specific transport service provider. The xbHTTPServer class is inherited from xbServer which in turn is inherited from xbSocket and Thread. An instance of this class will therefore have access to all methods and properties of it's superclasses. For information on the Thread class, please consult your Xbase++ documentation. All parameters are optional. Parameters: xLocalAddr The local address can be specified either as a numeric address in network byte order, or as an IP address in form of a dotted octet string (ex. 127.0.0.1). If an application does not care what local address is assigned, specify the constant value INADDR_ANY (the default). This allows the underlying service provider to use any appropriate network address. nPort This is the numeric port number on the local computer to bind the socket to. If not supplied, the default is 80 (or 443 when using an xbSSLContext) which are the standard port numbers for HTTP and HTTPS respectfully. oSSLContext In order to secure data transmission and possibly authenticate clients, an instance of xbSSLContext can be passed using this parameter. cName Optional descriptive name to associate with the thread instance. See Xbase++ documentation Thread:Name.
:ServerName
readonly/character
Contains server name and version number, eg. Xb2.NET/0.0.54
:RootDir( [cPath] ) -> cPath
Get/set default root directory for HTTP server. If not specified, the default is the current path where the
webserver application is running.
:StatusText( nStatusCode ) -> cStatusText
Return a text message corresponding to an HTTP response status code. An HTTP status code is a 3-digit integer
where the first digit defines the class of response. There are 5 values for the first digit (the remaining
two digits are not categorized):
1xx: Informational - Request received, continuing process
2xx: Success - The action was successfully received, understood, and accepted
3xx: Redirection - Further action must be taken to complete the request
4xx: Client Error - The request contains bad syntax or cannot be fulfilled
5xx: Server Error - The server failed to fulfill an apparently valid request
Configuration
:AllowDelete
exported/logical
When set to .T., client is permitted to delete a file on the HTTP server by using the DELETE method. The
target file is specified in the URI request. This property is ignored when the :onDELETE ivar contains
a codeblock. The default value is .F.
:AllowTrace
exported/logical
When set to .T., client is permitted to submit HTTP TRACE requests. The default is .F., ie. the TRACE
command is disabled. The HTTP TRACE command is used for testing and debugging. When an HTTP TRACE
request is sent to a web server that supports it, that server will respond echoing the data that is
passed to it, including any HTTP headers. It is recommended that TRACE be only supported in a test
environment since it is theoretically possible for a client to use HTTP TRACE for cross-site-scripting
attacks.
:AllowUpload
exported/logical
When set to .T., client is permitted to upload a file to the HTTP server by using the PUT method. The
target file is specified in the URI request, with the file contents contained within the body of the request.
This property is ignored when the :onPUT ivar contains a codeblock. The default value is .F.
:CompressedFilePrefix
exported/character
Specifies the file prefix to be used when saving temporary compressed versions of files found within :RootDir.
Web server files are automatically compressed as they are requested. In order to save CPU cycles for future requests, a copy of the compressed file is saved within the same directory using a hidden attribute and a unique file name prefix. When a compressed version already exists, the server will compare the timestamp with the original file to determine if the compressed version is stale. The default file name prefix used is "~", eg:
Original file: d:\www_root\index.htm
Temporary compressed version (hidden): d:\www_root\~index.htm
:CompressHttp10
exported/logical
This property enables or disables compression for requests containing an HTTP 1.0 version number.
HTTP 1.0, as described in RFC 1945, provides a minimal level of support for certain types of compression. However, some confusion exists around HTTP 1.0 compression, especially with regard to proxy servers. To minimize the chance of inappropriately returning a compressed file to a client that cannot decompress it, you can use this property to disable compression in questionable scenarios.
The default value of this property is .F., meaning that compression is disabled for HTTP 1.0 requests.
:CompressLevel
exported/numeric
Sets the default compression level to be used when compressing HTTP content. Acceptable values are between 0 and
9, where 0 = no compression and 9 = highest compression. Although a higher compression level will result in
smaller data, it will also result in higher CPU utilization. Best performance can be achieved by setting the
compression level to 6 or 7. The default is 0 or no compression.
NOTE: Data compression is implemented by the open-source ZLIB.DLL library that uses the "deflate" method as
documented in RFC-1950.
:CompressTypes
exported/character
Specifies a list of HTTP content MIME types that will be automatically compressed when compression is enabled
(:CompressLevel > 0). The default is:
"text/html;text/xml;text/plain;text/sgml;text/rtf;text/vbscript;application/x-javascript;"
:IndexFile
exported/character | character array | NIL
This is the default file that will be returned to the client when no resource is requested. A single value
can be specified as a character string or multiple values as an array of character strings. When multiple
values are specified, the server will search the root directory for the first match. The default is:
{"default.htm", "default.html", "index.htm", "index.html", "main.htm", "main.html"}
Setting :IndexFile to NIL will cause all client requests with an empty URI path component to be routed
to the :onGET codeblock.
:SessionTag
exported/character
This is the tag name that will be used to track a session-state between the server and client. Each session
is identified by an ID that must be communicated between the server and client with each request-response
state. By default, an xbHTTPThread object will use cookies to maintain this session ID between states.
However, this may not always work since a client may have cookie support turned off. In such cases, the
session ID can be communicated between states by embedding the session ID in the URL (as a query parameter)
or as a hidden form variable within an HTML page. Each instance of the HTTP server can have a different
session tag identifier. The default is: _SID
:SessionTimeout
exported/numeric
Inactive session timeout in minutes. An inactive client xbSession object will be maintained in memory
for a minimum :SessionTimeout minutes. The default is 150 minutes (2.5 hours).
:SOAPParser
exported/reference to class function
This instance variable provides a reference to a SOAP parser class function. By default :SOAPParser
contains a reference to the xbSOAPEnvelope class function, however it can be used to
define a custom SOAP parser to be used instead of xbSOAPEnvelope. When instantiated, the init method of the
SOAP parser will receive a single character string parameter containing the SOAP envelope. If a custom class is
used, it should at minimum contain a GetVar method that returns the value of a SOAP parameter.
Example: oServer:SOAPParser := MySOAPParser()
CLASS MySOAPParser
EXPORTED:
INLINE METHOD init( cXMLString )
// code to parse the XML SOAP envelope
Return self
INLINE METHOD GetVar( cName )
// code to return value of input parameter cName
Return xValue
ENDCLASS
:TLog
exported/object | NIL
Provides a reference to the object that will be used for logging client requests. To enable transaction logging,
set :TLog to an instance of the xbTLog class. To disable or pause logging temporarily,
set :TLog to NIL.
Example:
oTLog := xbTLog():new()
oTLog:SetDir(".\LogFiles")
oServer := xbHTTPServer():new()
oServer:TLog := oTLog
:WorkerClass
exported/reference to class function
This instance variable provides a reference to a client socket handler class function. By default
:WorkerClass contains a reference to the xbHTTPThread class function, however it can be used
to define a custom client socket handler to be used instead of xbHTTPThread. When instantiated, the
init method of the worker class will receive two parameters: (1) a reference to the parent server object, and
(2) a numeric handle of the newly created socket. If a custom class is used, it should be derived either from
the xbSocket and Thread classes or from the xbHTTPThread class.
Example:
oServer:WorkerClass := MyHTTPHandler()
CLASS MyHTTPHandler FROM xbHTTPThread
EXPORTED:
INLINE METHOD Init(oParent, nHandle)
::xbHTTPThread:init(oParent, nHandle)
// add your custom init code here
Return self
// The :Execute method is where all the work is done, add your custom code here
INLINE METHOD Execute()
Local oRequest := ::HTTPRequest
Local oResponse := ::HTTPResponse
while !oRequest:Recv()
do case
case oRequest:Command == "GET"
// code to generate GET response
case oRequest:Command == "POST"
// code to generate POST response
case oRequest:Command == "HEAD"
// code to generate HEAD response
otherwise
// send command not implemented status code
oResponse:StatusCode := 501
endcase
oResponse:Send()
if !oRequest:KeepAlive
// client doesn't want to keep connection open
::Close()
endif
oResponse:Reset() // reinitialize object
end
Return self
ENDCLASS
Event Handling
:FilterRequest
exported/codeblock | NIL
When supplied, this optional codeblock will be executed right after an HTTP request is received and prior to
a response being generated. A :FilterRequest codeblock can be used to easily spy on all HTTP requests
and if desired, modify the request prior to it being processed by the default HTTP handler. If supplied, the
codeblock must return a logical value. A return value of .F. indicates that the codeblock has generated a
response and no additional processing is required (ie. the request will not be processed by the default HTTP
handler). A return value of .T. tells the default HTTP handler to process the request as usual. When
evaluated, the codeblock will receive one parameter; a reference to the connected xbHTTPThread object.
Example 1:
oServer:FilterRequest := {|o|FilterRequest(o)}
Function FilterRequest(oClient)
QOut( oClient:HTTPRequest:StartLine )
if "winnt" $ Lower(oClient:HTTPRequest:Path())
// don't allow access to system dir
oClient:HTTPResponse:ContentType("text/plain")
oClient:HTTPResponse:Content := "The POLICE has been dispatched!"
Return .F.
endif
Return .T.
Example 2:
The following function shows how to use :FilterRequest to do virtual hosting. It assumes that the hosted
websites are organized as follows:
/www_root/website1/...
/www_root/website2/...
/www_root/website3/...
etc...
For example if the 3 websites hosted are sqlexpress.net, xb2.net and alaska-software.com,
then the directory structure will be as follows:
/www_root/sqlexpress.net/...
/www_root/xb2.net/...
/www_root/alaska-software.com/...
oServer:RootDir("/www_root")
oServer:FilterRequest := {|o|VirtualHosting(o)}
Function VirtualHosting(oClient)
Local i
Local cHost := Lower(oClient:HTTPRequest:Host())
Local cPath := oClient:HTTPRequest:Path()
// strip out port numbers
if (i := At(':',cHost)) > 0
cHost := Left(cHost,i-1)
endif
// modify requested path
if cPath $ "/\" .or. Empty(cPath)
cPath := "/index.htm"
endif
cPath := "/" + cHost + cPath
oClient:HTTPRequest:Path(cPath)
Return .T.
:onDELETE
exported/codeblock | NIL
This is an optional codeblock that will be executed when a DELETE request is received. By default DELETE
requests are rejected unless :AllowDelete is set to .T. or a custom codeblock is assigned to the
:onDELETE ivar. When evaluated, the codeblock will receive one parameter; a reference to the connected
xbHTTPThread object.
Example:
oServer:onDELETE := {|o|DeleteFile(o)}
Procedure DeleteFile( oClient )
Local cRootDir := oClient:Parent:RootDir()
Local cFile := oClient:HTTPRequest:Path
cFile := cRootDir + iif(Left(cPath,1)=="/", SubStr(cPath,2), cPath)
oClient:HTTPResponse:ContentType("text/plain")
if FErase(cFile) == 0
oClient:HTTPResponse:Content := "File deleted"
else
oClient:HTTPResponse:Content := "Unable to delete file"
endif
Return
:onGET
exported/codeblock | NIL
This is an optional codeblock that is used to process dynamic requests. Client requests that fall under this
category include; (a) requests with a URI query component, and (b) requests with an empty URI path component
and no :IndexFile defined. If a dynamic request is received, and no :onGET codeblock is
defined, then the server will reply with a 404 status code. When evaluated, the supplied codeblock will
receive one parameter; a reference to the connected xbHTTPThread object.
:onHTTPError
exported/codeblock | NIL
This is an optional codeblock that will be executed when a runtime error occurs while processing the HTTP request.
If no custom codeblock is supplied, the default behavior is to log the error and return to the client a description
of the error including callstack information. If a codeblock is supplied and a runtime error occurs within the
connected client's xbHTTPThread, the codeblock will be evaluated with one parameter
passed; a reference to the Xbase++ Error object. The function evaluated within the supplied
codeblock must terminate with a Break(). If a character string is passed to the Break() function (as
in the example below), then this string will be transmitted to the client. Alternatively, if an error object is
passed, then the HTTP server will generate a corresponding reply.
Example:
oServer:onHTTPError := {|o|HTTPError(o)}
Procedure HTTPError( oError )
Local oClient := ThreadObject()
Local cCRLF := chr(10)+chr(13)
Local cResponse
oClient:HTTPResponse:ContentType("text/plain")
cResponse := "An error occurred in my Xbase++ web server:" + cCRLF +;
iif(ValType(oError:subSystem) == "C", oError:subSystem, "???" ) + "/" +;
iif(ValType(oError:subCode) == "N", Str(oError:subCode), "???" ) + cCRLF +;
iif(ValType(oError:description) == "C", oError:description, "" )
Break( cResponse )
Return
:onInvalidCommand
exported/codeblock | NIL
This is an optional codeblock that will be evaluated when a non-supported method is requested by the client. If
no custom codeblock is supplied, the default behavior is to reply with an HTTP 501 status code. When evaluated,
the supplied codeblock will receive one parameter; a reference to the connected xbHTTPThread object.
Example:
oServer:onInvalidCommand := {|o|MethodNotSupported(o)}
Procedure MethodNotSupported( oClient )
Local oResp := oClient:HTTPResponse
oResp:StatusCode := 501
oResp:ContentType := "text/plain"
oResp:Content := "The requested method is not supported!"
Return
:onLog
exported/codeblock | NIL
An optional codeblock that will be evaluated immediately after a client request is completed and just before the
transaction is to be logged. If supplied, the codeblock must return a logical value. A return value of .F.
indicates an entry should not be added to the log file for this transaction. A return value of .T. indicates to
proceed as usual; ie. if logging is enabled (see :TLog), then the transaction will be logged.
This codeblock can therefore be used to filter what gets logged to the transaction log file and/or to perform custom logging. When evaluated, the supplied codeblock will receive one parameter; a reference to the connected xbHTTPThread object.
Example:
oServer:onLog := {|o|OnLog(o)}
Function OnLog( oClient )
if oClient:InetNtoA(oClient:RemoteAddr) == "127.0.0.1"
// don't log requests originating from localhost
Return .F.
endif
Return .T.
:onNotFound
exported/codeblock | NIL
This is an optional codeblock that will be evaluated when a requested resource is not found. If no custom
codeblock is supplied, the default behavior is to reply with an HTTP 404 status code. When evaluated, the
supplied codeblock will receive one parameter; a reference to the connected xbHTTPThread object.
Example:
oServer:onNotFound := {|o|FileNotFound(o)}
Procedure FileNotFound( oClient )
Local oReq := oClient:HTTPRequest
Local oResp := oClient:HTTPResponse
if oReq:Path == "/~5" .or. oReq:Path == "\~5"
// redirect user to the new location
oResp:Location := "http://www.SomeOtherLocation.com"
oResp:StatusCode := 301
else
oResp:StatusCode := 404
oResp:ContentType := "text/plain"
oResp:Content := "The requested file is not found!"
endif
Return
:onPOST
exported/codeblock | NIL
This is an optional codeblock that is used to process POST commands. If a POST command is received, and an
:onPOST codeblock is not defined, then the server will reply with a 501 status code. When evaluated,
the supplied codeblock will receive one parameter; a reference to the connected xbHTTPThread object.
:onPUT
exported/codeblock | NIL
This is an optional codeblock that will be executed when a PUT request is received. By default PUT
requests are rejected unless :AllowUpload is set to .T. or a custom codeblock is assigned to the
:onPUT ivar. When evaluated, the codeblock will receive one parameter; a reference to the connected
xbHTTPThread object. See :onDELETE for an example.
:onSessionClose
exported/codeblock | NIL
An optional codeblock that will be executed just before a client xbSession object is closed.
When executed, one parameter is passed to the codeblock; a reference to the array containing the terminated session's data.
:onSOAP
exported/codeblock | NIL
This is an optional codeblock that is used to process SOAP requests. If a SOAP request is received, and an
:onSOAP codeblock has not been assigned, then the :onPOST codeblock will be evaluated. If that
is also not defined, then the server will reply with a 501 status code. When evaluated, the supplied
codeblock will receive one parameter; a reference to the connected xbHTTPThread object.
Example: oServer:onSOAP := {|o| SOAPHandler(o)}
Procedure SOAPHandler( oClient )
Local cAction, oSOAPReq, oSOAPResp
// :HTTPRequest:Content contains an xbSOAPEnvelope instance
oSOAPReq := oClient:HTTPRequest:Content
// this is the action requested by the client
cAction := oSOAPReq:Action
// create another SOAP envelope object where we will write our response
oSOAPResp := xbSOAPEnvelope():new()
// tack on the word "Response" to the reply envelope action, eg. "GetDateTimeResponse"
oSOAPResp:Action := cAction + "Response"
do case
case cAction == "GetDateTime"
oSOAPResp:SetVar("Date", Date())
oSOAPResp:SetVar("Time", Time())
case cAction == "SQLExecute"
if Empty(oSOAPReq:GetVar("SQLStatement"))
// the parameter is missing - send back an appropriate fault response.
oSOAPResp:SetFault("Client", "SQLStatement parameter is missing")
else
nResult := DefaultSQLConnection():Execute( oSOAPReq:GetVar("SQLStatement") )
oSOAPResp:SetVar("Result", nResult)
endif
otherwise
// requested method is not available - send back a fault response.
oSOAPResp:SetFault("Client", "Client request " + cAction + " not available")
endcase
// attach the SOAP response envelope to the HTTP response object
// the Xb2.NET HTTP server will take care of the rest
oClient:HTTPResponse:Content := oSOAPResp
Return
inherited from xbSocket and Thread
This is the client thread that is spawned by xbServer when a connection with a peer is accepted. This "worker" thread will handle the request and send a response back to the connected client.
:New([nAddrFamily], [nSocketType], [nProtocol], [oSSLContext], [cName]) -> self, or;
:New(oParent, [nHandle],,, [cName]) -> self
Creates a new instance of the xbSocketThread class and allocates system resources to bind the newly created socket
to a specific transport service provider. The xbSocketThread class is inherited from xbSocket
and Thread (part of Xbase++). An instance of this class will therefore have access to all methods
and properties of it's superclasses. For information on the Thread class, please consult your
Xbase++ documentation. For additional information on parameters, please see xbSocket:New().
All parameters are optional.
cName
Optional descriptive name to associate with the thread instance. See Xbase++ documentation Thread:Name.
:Start([cFuncName|bCodeBlock], [xParamList,...] ) -> lSuccess Starts the thread and executes the function cFuncName or evaluates the code block bCodeBlock within this thread. The parameters xParamList are passed on to the function or codeblock, respectively. If the thread is started successfully, the method returns .T., otherwise it returns .F.
Once started the xbSocketThread will continue executing the code encapsulated by the specified function or codeblock until the socket is either disconnected by the remote host or, the thread is terminated by calling the :Stop method. Once the thread has stopped, it can be restarted by calling :Start. As long as the thread is active, repeated calls to :Start are ignored.
If neither cFuncName or bCodeBlock are supplied, then the default behavior is to simply echo back to the connected peer all received data. The following is an example of a server type socket thread that implements two commands "GET TIME" and "GET DATE":
Example:
oSocket:Start("ServiceClient", oSocket)
Procedure ServiceClient( oSocket )
Local cRecv, cSend
while (cRecv := oSocket:RecvLine()) != NIL
cRecv := Upper(Left(cRecv,8))
do case
case cRecv == "GET TIME"
cSend := Time()
case cRecv == "GET DATE"
cSend := DToS(Date())
otherwise
cSend := cRecv + " invalid command"
endcase
if oSocket:Send( cSend ) < 0
exit
endif
end
Return
:Stop([nTimeOut]) -> lSuccess
Close socket and signal socket thread to terminate. nTimeOut is an optional parameter specifying the
maximum amount of time, in 1/100ths of a second, to wait for the xbSocketThread thread to terminate.
The default value of zero causes the current thread (where :Stop was called) to wait indefinitely
until the xbSocketThread thread has terminated. The method returns .F. if the thread could not be
terminated within the specified time interval, otherwise it returns .T.
:ThreadID
readonly/numeric
Numeric ID of thread.
inherited from xbSocket and Thread
This is the client thread that is spawned by xbHTTPServer when a connection is accepted from a user agent (a browser). This "worker" thread is responsible for handling the client request and generating an appropriate xbHTTPResponse that will be sent back to the client. Typically, there is no need to instantiate this class in your code since it is automatically instantiated by the xbHTTPServer when a client connection is accepted.
:New([nAddrFamily], [nSocketType], [nProtocol], [oSSLContext], [cName]) -> self, or;
:New(oParent, [nHandle],,, [cName]) -> self
Creates a new instance of the xbHTTPThread class and allocates system resources to bind the newly created
socket to a specific transport service provider. The xbHTTPThread class is inherited from
xbSocket and Thread (part of Xbase++). An instance of this class will therefore have access to
all methods and properties of it's superclasses. For information on the Thread class, please consult
your Xbase++ documentation. For additional information on parameters, please see xbSocket:New(). All
parameters are optional.
cName
Optional descriptive name to associate with the thread instance. See Xbase++ documentation Thread:Name.
Life Cycle :Start([cFuncName|bCodeBlock], [xParamList,...] ) -> lSuccess Starts the HTTP server thread. If the thread is started successfully, the method returns .T., otherwise it returns .F. Once started the xbHTTPThread will continue running until the socket is either disconnected by the remote host or, the thread is terminated by calling the :Stop method. Once the thread has stopped, it can be restarted by calling :Start. As long as the thread is active, repeated calls to :Start are ignored. :Stop([nTimeOut]) -> lSuccess Close socket and signal socket thread to terminate. nTimeOut is an optional parameter specifying the maximum amount of time, in 1/100ths of a second, to wait for the xbHTTPThread thread to terminate. The default value of zero causes the current thread (where :Stop was called) to wait indefinitely until the xbHTTPThread thread has terminated. The method returns .F. if the thread could not be terminated within the specified time interval, otherwise it returns .T. Send Reply :NotFound() -> nBytesSent | SOCKET_ERROR Send default HTTP 404 error message to client. :Send([cBuffer], [nFlag], [xToAddr], [nToPort]) -> nBytesSent | SOCKET_ERROR Transmit data provided in cBuffer to connected client. If cBuffer is NIL or not specified, the method will send the data contained in the :HTTPResponse object (the other parameters are ignored). In most cases, there is no need to call this method since it will be called automatically by the xbHTTPThread object. For a detailed explanation of all parameters, see xbSocket:Send() :SendBusy() -> self Send default server busy response to client and close connection. :SendError(xError) -> self Send error message to client and close connection. xError can be either a string or an Xbase++ error object. :SendFile(cFile) -> nBytesSent | SOCKET_ERROR This method transmits a file to the client. The file path must be relative to the directory where the HTTP server application is running. If cFile is not found, then an HTTP 404 status code will be sent instead. State Management
Session or state management involves saving persistent data across multiple HTTP requests. The automatic session management performed by the xbHTTPServer class relies on one "session" cookie containing a session ID which is passed to the client. Please note that session cookies are not permanent, they are removed from the client's browser cache when the last browser window (within the same process) is closed.
Automatic session management using cookies is simple to implement since it requires no additional coding by the programmer. However if cookie support is turned off on the client side, then the session ID will be lost. To overcome this problem, some additional code will need to be added to the web application to keep track of the session ID. This is fairly easy to implement but unfortunately it cannot be done automatically by Xb2.NET. To keep track of the session ID without using cookies do this:
Example:
Procedure WEB_Test1()
Local cID
Local oClient := ThreadObject()
if oClient:GetCargo("message") == NIL
oClient:SetCargo("message", "Session start time:" + time())
endif
cID := oClient:GetSessionHandle()
oClient:HTTPResponse:Content := "<html><body><a href=Test2?_SID=" + cID + ">Click here</a></body></html>"
Return
Procedure WEB_Test2()
Local oClient := ThreadObject()
oClient:HTTPResponse:Content := "<html><body>" + oClient:GetCargo("message") + "</body></html>"
Return
To use a different variable name (other that "_SID"), then set xbHTTPServer:SessionTag to the new name, eg:
oMyHTTPServer:SessionTag := "RANDOM" :OpenSession() -> self Open existing client session or create a new one if none exists. Session data is stored in server memory until the session is either closed using :CloseSession or the session times out (see xbHTTPServer:SessionTimeout). NOTE: Calling :GetCargo or :SetCargo automatically opens a session. :NewSession([lCloseExisting]) -> self Create brand new session. The optional logical parameter lCloseExisting can be set to .F. (false) in order to leave a current existing session open while creating a brand new session.
If not provided, the default value for lCloseExisting is .T. (true), meaning that the client's current session will be closed prior to creating a new session. This is equivalent to calling :CloseSession() followed by :OpenSession().
Warning: Setting lCloseExisting to .F. (false) will leave an existing session open, while opening a new one. Since sessions are maintained in memory and are not closed until a predetermined time of inactivity has elapsed, this setting has the potential of consuming more memory than normally required. If this functionality is indeed required, it is suggested that the xbHTTPServer:SessionTimeout be reduced. :CloseSession() -> self Close session and release any state variables maintained in memory by the xbSession class for this client. :GetSessionHandle() -> cSessionID | NIL Returns client session ID as a string or NIL if there is no session currently open for this client. :GetCargo([cName]) -> xValue | aVarList | NIL Retrieve a named state variable previously saved with :SetCargo. If a parameter is not supplied or if cName is NIL, then the method will return an array of all name/value pairs saved in the current xbSession object. Note, this method will open a new session if none exists. :SetCargo([xName], [xValue]) -> xPreviousValue | aPreviousVarList Store the value xValue using a symbolic character name xName until the session is closed. This method is quite flexible and can be used is several ways:
When xName and xValue are both NIL then delete all state variables (session is not closed)
When xValue is NIL, state variable with the name xName is deleted
When xName is an array, replace all name/value pairs with passed array
Otherwise add/replace value
This method will open a new session if none exists. Data :GetCookie([cName]) -> cValue | aCookieList | NIL This method is a shortcut to xbHTTPThread:HTTPRequest:GetCookie(). Please see the xbHTTPRequest class for more information. :SetCookie([cName],[cValue],[dExpiry],[cPath],[cDomain],[lSecure]) -> cPreviousValue | aPrevCookieList This method is a shortcut to xbHTTPThread:HTTPResponse:SetCookie(). Please see the xbHTTPResponse class for more information. :GetVar([cName],[nSource]) -> cValue | aVarList | NIL Retrieve a named parameter contained within the HTTP request. If cName is NIL, then the method will return an array of name/value pairs transmitted by the client as URL query parameters.
Named parameters can be transmitted by the client as a query within the URL, eg: (http://ca.finance.yahoo.com/q?s=NT.TO&d=c&k=c4&t=1d) or as form variables within the body of the request. The optional nSource parameter can be used to specify where to retrieve the value from. If not specified the parameter will first be searched within the URL query then within the form (if available). The method will return the first value found matching the name cName or NIL if the parameter is not found. The following Xb2NET.CH define constant are provided for this purpose:
VAR_QUERY - search within URL query parameter list
VAR_CONTENT - search within the body of the HTTP request.
VAR_ANY - first search the URL query, then within the body of the HTTP request.
:HTTPRequest
readonly/object
Reference to xbHTTPRequest object. This object encapsulates the client request that was sent to the HTTP server.
:HTTPResponse
readonly/object
Reference to xbHTTPResponse object. This object encapsulates the server response that will be sent to the client.
:isSOAP
readonly/logical
This instance variable will be .T. when the request contains a SOAP Action. In all other cases it's value will be .F.
abstract class
This is an abstract class that provides a common foundation for the xbHTTPRequest and xbHTTPResponse classes.
:Reset([oSocket]) -> self Reinitialize object. :GetHeader([cName]) -> cValue | aHeaderList | NIL This is a generic method for retrieving HTTP header fields. If cName is NIL, then the method will return an array of name/value pairs representing all header fields. :SetHeader([cName], [cValue]) -> cPreviousValue | aPreviousHeaderList This is a generic method for setting HTTP header fields. This method can be used is several ways:
When cName and cValue are both NIL then delete all headers.
When cValue is NIL, header parameter with the name cName is deleted.
When cName is an array, replace all headers with passed array.
Otherwise add/replace value
:GetCookie([cName]) -> cValue | aCookieList | NIL
Retrieve the value of a cookie with the name cName. If a parameter is not supplied or if
cName is NIL, then the method will return an array of name/value pairs representing all cookies.
:ClearContent()
Clear the :Content buffer and remove all content related header fields.
:GetContentAsString()
Retrieve the HTTP message content as a character string.
:ParseHeader( cHeader )
Parse message header. This is done automatically when a message is received using :Recv().
:AsString() -> cHTTPMessage
Encode header and content suitable for HTTP transport and return as character string.
:Send() -> nBytesSent | SOCKET_ERROR
Encode header and content for HTTP transport and transmit to connected peer.
:SendChunk([cData], [cExtension]) -> nBytesSent | SOCKET_ERROR
Transmit a chunk of data to connected peer using "chunked" transfer encoding. Sending data as chunks allows
dynamically produced content to be transferred to the recipient incrementally. In order to use this method,
the message header must have the TransferEncoding field set to "chunked". The message header is transmitted
first using :Send(), followed by the individual chunks of data. When no more data remains, a final empty
chunk must be sent to indicate the end of content. cData is a character string representing the chunk
of data to be transmitted, and cExtension is a character string used to attach additional attributes
and/or to indicate that an encoding transformation has been applied to the chunk. Both parameters are optional.
Example:
Procedure WEB_SendChunks()
Local i, oResponse := ThreadObject():HTTPResponse
// add a transfer-encoding header field and set it to "chunked"
oResponse:TransferEncoding('chunked')
// send the message header
oResponse:Send()
// send first chunk of content
oResponse:SendChunk('<html><head><title>Sending Chunks</title></head><body>')
for i := 1 to 10
oResponse:SendChunk('<p>This is chunk #' + Str(i))
next
oResponse:SendChunk('<p>All done</body></html>')
// send an empty chunk to signal end of content
oResponse:SendChunk()
Return
:Recv([xFile]) -> lSuccess
Read message transmitted by remote peer and parse message header from content. The method returns .T. if data was
successfully received.
The optional parameter xFile determines how the HTTP message content is saved. If xFile is provided, then the content will be saved in a file, otherwise it will be saved in the instance variable :Content.
The file where received data is saved can be specified as either a numeric handle as returned by FOpen() or FCreate(), or as a character string denoting the file name and path. NOTE: If a file handle is provided, then received data will be saved starting at the current file pointer offset. On return, the file will be left open and the file pointer will be positioned on the last byte written. If a file name is specified instead of a numeric handle, then the file will be closed.
:BytesReceived
exported/numeric
Number of bytes received by last :Recv call.
:BytesSent
exported/numeric
Number of bytes transmitted by last :Send call.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:Content
exported/character or object
Message content. Can be a character string or an object.
:CompressLevel
exported/numeric
Sets the default compression level to be used when compressing HTTP content. Acceptable values are between 0 and
9, where 0 = no compression and 9 = highest compression. Although a higher compression level will result in
smaller data, it will also result in higher CPU utilization. Best performance can be achieved by setting the
compression level to 6 or 7. The default is 0 or no compression.
NOTE: Data compression is implemented by the open-source ZLIB.DLL library that uses the "deflate" method as
documented in RFC-1950.
:CompressTypes
exported/character
Specifies a list of HTTP content MIME types that will be automatically compressed when compression is enabled
(:CompressLevel > 0). The default is:
"text/html;text/xml;text/plain;text/sgml;text/rtf;text/vbscript;application/x-javascript;"
:HTTPVersion
exported/character
The HTTP protocol version of the message, eg. "1.1"
:Message
exported/character
Complete HTTP header as a character string.
:Socket
exported/object
Reference to the connected xbSocket object. Depending on the context, the peer can be either the server or
the client.
:StartLine
exported/character
First line in HTTP message.
Header fields (access/assign methods)
:CacheControl
exported access-assign method/character
Get/set the "Cache-Control" header field. This general-header field is used to control the caching mechanisms
along the message route. It can be used to prevent caches from adversely interfering with the request or
response. See RFC-2616, 14.9.
:Connection
exported access-assign method/character
Get/set the "Connection" header field. This general-header field allows the sender to specify options that
are desired for that particular connection. It can be used with HTTP 1.1 to keep persistent connections. See
RFC-2616, 14.10.
:ContentEncoding
exported access-assign method/character
Get/set the "Content-Encoding" header field. This header field applies to the message content and is is used
as a modifier to the media-type. When present, its value indicates what additional content codings have been
applied to the entity-body, and thus what decoding mechanisms must be applied in order to obtain the
media-type referenced by the Content-Type header field. See RFC-2616, 14.11.
:ContentLanguage
exported access-assign method/character
Get/set the "Content-Language" header field. This header field applies to the message content and is used to
describe the natural language(s) of the intended audience for the enclosed entity. Note that this might not
be equivalent to all the languages used within the entity-body. See RFC-2616, 14.12.
:ContentLength
exported access-assign method/numeric
Get/set the "Content-Length" header field. This header field indicates the size of the message content sent
to the recipient. See RFC-2616, 14.13.
:ContentLocation
exported access-assign method/character
Get/set the "Content-Location" header field. This header field may be used to supply the location for the
entity enclosed in the message when that entity is accessible from a location separate from the requested
resource's URI. See RFC-2616, 14.14.
:ContentMD5
exported access-assign method/character
Get/set the "Content-MD5" header field. This header field is used for the purpose of providing an end-to-end
message integrity check of the content. See RFC-2616, 14.15.
:ContentRange
exported access-assign method/character
Get/set the "Content-Range" header field. This header field is sent with a partial entity-body to specify
where in the full entity-body the partial body should be applied. See RFC-2616, 14.16.
:ContentType
exported access-assign method/character
Get/set the "Content-Type" header field. This header field indicates the media type of the message content sent
to the recipient or, in the case of the HEAD command, the media type that would have been sent had the request
been a GET. See RFC-2616, 14.17.
:KeepAlive
exported access-assign method/logical
Get/set the "Connection" header field. When .T. it indicates that the sender requests a persistent connection.
:LastModified
exported access-assign method/character
Get/set the "Last-Modified" header field. This header field is used to indicate the date and time at which
the message content was last modified. See RFC-2616, 14.29.
:Pragma
exported access-assign method/character
Get/set the "Pragma" header field. This header field is used to include implementation-specific directives
that might apply to any recipient along the message path. See RFC-2616, 14.32.
:ProxyConnection
exported access-assign method/character
Get/set the "Proxy-Connection" header field. This header field is only used in HTTP/1.0. It has been
superseded by the "Connection" header field in HTTP/1.1
:Trailer
exported access-assign method/character
Get/set the "Trailer" header field. This is a general header field whose value indicates that the given set
of header fields is present in the trailer of a message encoded with chunked transfer-coding. See RFC-2616,
14.40.
:TransferEncoding
exported access-assign method/character
Get/set the "Transfer-Encoding" header field. This is a general header field indicating what (if any) type of
transformation has been applied to the message body in order to safely transfer it between the sender and the
recipient. This differs from the content-coding in that the transfer-coding is a property of the message, not
of the entity. See RFC-2616, 14.41.
:Via
exported access-assign method/character
Get/set the "Via" header field. This is a general header field that indicates the intermediate protocols and
recipients between the client and server on requests, and between the server and client on responses. See
RFC-2616, 14.45.
:Warning
exported access-assign method/character
Get/set the "Warning" header field. This is a general header field that is used to carry additional
information about the status or transformation of a message which might not be reflected in the message. See
RFC-2616, 14.46.
inherited from xbHTTPMessage and xbURI
This class encapsulates an HTTP request. It can be used on the client side to compose and send a request to an HTTP server, and on the server side it is used to receive and parse the HTTP request sent by the client.
:New([oSocket]) -> self Creates a new instance of the xbHTTPRequest class. The optional parameter oSocket is a reference to an xbSocket object that must be supplied in order to use the :Send and/or :Recv methods.
:SetCookie([cName],[cValue]) -> cPreviousValue | aPrevCookieList This method is used on the client side to return a previously saved cookie value back to the HTTP server. An HTTP server will request that a cookie be stored on the client side by using the xbHTTPResponse:SetCookie method. Cookies are typically used by HTTP servers to store state information on the client side. This method can be used is several ways:
When cName and cValue are both NIL then remove all cookies from internal array.
When cValue is NIL, then remove the cookie with name cName from internal array.
When cName is an array, replace all cookie name/value pairs with passed array.
Otherwise add or replace a cookie value.
:Command
exported/character
This is the HTTP method requested, eg: GET, HEAD, POST, PUT, DELETE, TRACE, CONNECT
:isSOAP
readonly/logical
This instance variable will be .T. when the received request contains a SOAP Action. In all other cases it's
value will be .F.
Header fields (access/assign methods)
:Accept
exported access-assign method/character
Get/set the "Accept" header field. This header field can be used by the client to specify certain
media types which are acceptable for the response. See RFC-2616, 14.1.
:AcceptCharset
exported access-assign method/character
Get/set the "Accept-Charset" header field. This header field allows a client to specify what character
sets is is capable of understanding. See RFC-2616, 14.2.
:AcceptEncoding
exported access-assign method/character
Get/set the "Accept-Encoding" header field. This request header field is similar to :Accept,
but restricts the content codings that are acceptable in the response. See RFC-2616, 14.3.
:AcceptLanguage
exported access-assign method/character
Get/set the "Accept-Language" header field. This request header field is similar to :Accept,
but restricts the set of natural languages that are preferred in the response. See RFC-2616, 14.4. Language
tags are defined in RFC-1766.
:Authorization
exported access-assign method/character
Get/set the "Authorization" header field. It is used by a client to authenticate itself with a server.
The field is usually, but not necessarily, included with the request after receiving a 401 response. The
Authorization field value consists of credentials containing the authentication information of the client for
the realm of the resource being requested. See RFC-2616, 14.8.
:Expect
exported access-assign method/character
Get/set the "Expect" header field. This header field is used to indicate that particular server
behaviors are required by the client. A "100-continue" token can be used by a client sending a request
message with a request body to determine if the server is willing to accept the request (based on the request
headers) before the client sends the request body. In some cases, it might either be inappropriate or highly
inefficient for the client to send the body if the server will reject the message without looking at the
body. See RFC-2616, 14.20.
:Host
exported access-assign method/character
Get/set the "Host" header field. The Host request-header field specifies the HTTP host and port number
of the resource being requested, as obtained from the original URI given by the user or referring resource.
The :Host is equivalent to the xbURI:Authority portion of a URI. See RFC-2616, 14.23.
:IfMatch
exported access-assign method/character
Get/set the "If-Match" header field. This header field is used to make an HTTP command conditional. As
an example it can be used by clients to efficiently update cached information with a minimum amount of
transaction overhead. See RFC-2616, 14.24.
:IfModifiedSince
exported access-assign method/character Get/set the "If-Modified-Since" header field.
This header field is used to make an HTTP command conditional. If the requested variant has not been modified
since the time specified in this field, an entity will not be returned from the server; instead, a 304 (not
modified) response will be returned without any message-body. See RFC-2616, 14.25.
:IfNoneMatch
exported access-assign method/character
Get/set the "If-None-Match" header field.
See RFC-2616, 14.26.
:IfRange
exported access-assign method/character
Get/set the "If-Range" header field.
See RFC-2616, 14.27.
:IfUnmodifiedSince
exported access-assign method/character
Get/set the "If-Unmodified-Since" header field.
See RFC-2616, 14.28.
:MaxForwards
exported access-assign method/character
Get/set the "Max-Forwards" header field.
See RFC-2616, 14.31.
:ProxyAuthorization
exported access-assign method/character
Get/set the "Proxy-Authorization" header field. This request header field is used by a client to
identify itself to a proxy which requires authentication. The field is usually, but not necessarily, included
with the request after receiving a 407 response. The :ProxyAuthorization field value consists of
credentials containing the authentication information of the client for the proxy and/or realm of the
resource being requested. See RFC-2616, 14.34.
:Range
exported access-assign method/character
Get/set the "Range" header field.
See RFC-2616, 14.35.
:Referrer
exported access-assign method/character
Get/set the "Referer" header field. This request-header field allows the client to specify, for the
server's benefit, the address (URI) of the resource from which the Request-URI was obtained.
See RFC-2616, 14.36.
:TE
exported access-assign method/character
Get/set the "TE" header field.
See RFC-2616, 14.39.
:UserAgent
exported access-assign method/character
Get/set the "User-Agent" header field. This header field contains information about the user agent
(client) originating the request. It is used for statistical purposes, the tracing of protocol violations,
and automated recognition of user agents for the sake of tailoring responses to avoid particular user agent
limitations. See RFC-2616, 14.43.
:UserEmail
exported access-assign method/character
Get/set the "From" header field.
See RFC-2616, 14.22.
:SOAPAction
exported access-assign method/character
Get/set the "SOAPAction" header field. Most HTTP servers that also provide SOAP services use this
request header field to differentiate between a SOAP request and a normal web request. In most cases the
content of the header field is not important, but as a general rule it should be the same as the SOAP method
requested.
inherited from xbHTTPMessage
This class encapsulates an HTTP response. It can be used on the server side to compose and send an HTTP response to a connected client, and on the client side to receive and parse the HTTP response that was sent by the server.
:New([oSocket]) -> self Creates a new instance of the xbHTTPResponse class. The optional parameter oSocket is a reference to an xbSocket object that must be supplied in order to use the :Send and/or :Recv methods.
:SetCookie([cName],[cValue],[dExpiry],[cPath],[cDomain],[lSecure]) -> cPreviousValue | aPrevCookieList This method is used on the server side to store a cookie value on the client side. Cookies are typically used by HTTP servers to store state information on the client side. This method can be used is several ways:
When cName and cValue are both NIL then remove all cookies from internal array.
When cValue is NIL, then remove the cookie with name cName from internal array.
When cName is an array, replace all cookie name/value pairs with passed array.
Otherwise add or replace a cookie value.
Parameters:
cName
The name of the cookie.
cValue
A character string representing the cookie data to be saved in the browser's cache.
dExpiry
The expiration date of the cookie. If an expiration date is not set, the cookie expires after the Internet session ends.
Otherwise, the cookie is persisted in the browser's cache until the expiration date. To delete a persistent cookie from
the browser's cache, set dExpiry to a date in the past, eg:
oResponse:SetCookie("mycookie","",stod("19900101"))
cPath
Setting the path, is optional and can be used to specify a subset of the URLs for which the cookie is valid. If a path
is specified, the cookie is considered valid for any requests that match that path. For example, if the specified path is
/example, requests with the paths /examplecode and /example/code.htm would match. If no path is specified, the path is
assumed to be the path of the resource associated with the SetCookie header.
cDomain
Specifying the domain name, is optional for persistent cookies and is used to indicate the end of the domain for which
the cookie is valid. Session cookies that specify a domain are rejected. If the specified domain name ending matches the
request, the cookie tries to match the path to determine if the cookie should be sent. For example, if the domain name
ending is .microsoft.com, requests to home.microsoft.com and support.microsoft.com would be checked to see if the specified
pattern matches the request. The domain name must have at least two or three periods in it to prevent cookies from being
set for widely used domain name endings, such as .com, .edu, and co.jp. Allowable domain names would be similar to
.microsoft.com, .someschool.edu, and .someserver.co.jp. Only hosts within the specified domain can set a cookie for a domain.
lSecure
The cookie can be marked as secure so that it will only be sent to HTTPS servers. If lSecure is not specified or is
set .F., a cookie is considered safe to be sent in the clear over unsecured channels.
StatusCode
exported/numeric
The StatusCode is a 3-digit integer result code of the attempt to understand and satisfy the request.
The first digit defines the class of response while the remaining two digits are not categorized. There are 5
values for the first digit:
1xx: Informational - Request received, continuing process
2xx: Success - The action was successfully received, understood, and accepted
3xx: Redirection - Further action must be taken to complete the request
4xx: Client Error - The request contains bad syntax or cannot be fulfilled
5xx: Server Error - The server failed to fulfill an apparently valid request
:StatusText
exported/character
This is a short textual description of the :StatusCode, eg:
100: Continue
101: Switching Protocols
200: OK
201: Created
202: Accepted
203: Non-Authoritative Information
204: No Content
205: Reset Content
206: Partial Content
300: Multiple Choices
301: Moved Permanently
302: Found
303: See Other
304: Not Modified
305: Use Proxy
307: Temporary Redirect
400: Bad Request
401: Unauthorized
402: Payment Required
403: Forbidden
404: Not Found
405: Method Not Allowed
406: Not Acceptable
407: Proxy Authentication Required
408: Request Time-out
409: Conflict
410: Gone
411: Length Required
412: Precondition Failed
413: Request Entity Too Large
414: Request-URI Too Large
415: Unsupported Media Type
416: Requested range not satisfiable
417: Expectation Failed
500: Internal Server Error
501: Not Implemented
502: Bad Gateway
503: Service Unavailable
504: Gateway Time-out
505: HTTP Version not supported
Header fields (access/assign methods)
:AcceptRanges
exported access-assign method/character
Get/set the "Accept-Ranges" header field.
See RFC-2616, 14.5.
:Age
exported access-assign method/character
Get/set the "Age" header field. This response-header field conveys the sender's estimate of the amount
of time in integer seconds since the response was generated at the origin server. See RFC-2616, 14.6.
:Allow
exported access-assign method/character
Get/set the "Allow" header field. This field lists the set of methods supported by the resource
identified by the Request-URI. The purpose is to inform the recipient of commands that are supported by the
resource. See RFC-2616, 14.7.
:ETag
Get/set the "ETag" header field.
See RFC-2616, 14.19.
:Expires
exported access-assign method/character
Get/set the "Expires" header field. This header field gives the date/time after which the message
content is considered stale. See RFC-2616, 14.21.
:Location
exported access-assign method/character
Get/set the "Location" header field. It is used to redirect the client to a location other than the
Request-URI for completion of the request. For 201 (Created) responses, the Location is that of the new
resource which was created by the request. For 3xx responses, the location should indicate the server's
preferred URI for automatic redirection to the resource. The field value consists of a single absolute URI.
See RFC-2616, 14.30.
:ProxyAuthenticate
exported access-assign method/character
Get/set the "Proxy-Authenticate" header field.
See RFC-2616, 14.33.
:Refresh
exported access-assign method/character
Get/set the "Refresh" header field. Although this header field is not part of RFC-2616, it is
supported by most browsers. By including this header field in a HTTP response, a client can be triggered to
automatically fetch information from a server. This is often referred to as "client pull".
Examples:
// refresh page after 60 seconds
oClient:HTTPResponse:Refresh("60")
// display page then after 3 seconds display Login.htm
oClient:HTTPResponse:Refresh("3; URL=Login.htm")
// display page then after 10 seconds redirect user to www.mysite.com
oClient:HTTPResponse:Refresh("10; URL=http://www.mysite.com")
:RetryAfter
exported access-assign method/character
Get/set the "RetryAfter" header field. This response-header field can be used with a 503
(Service Unavailable) response to indicate how long the service is expected to be unavailable. It may also be
used with any 3xx (Redirection) response to indicate the minimum time the client is asked wait before issuing
the redirected request. The value of this field can be either an HTTP-date as returned by xbGMTDate or
an integer number of seconds after the time of the response. See RFC-2616, 14.37.
:Server
exported access-assign method/character
Get/set the "Server" header field. This header field contains information about the software used by
the origin server to handle the request. See RFC-2616, 14.38.
:Vary
exported access-assign method/character
Get/set the "Vary" header field.
See RFC-2616, 14.44.
:WWWAuthenticate
exported access-assign method/character
Get/set the "WWW-Authenticate" header field.
See RFC-2616, 14.47.
This class provides a higher level interface for developing HTTP client applications. xbHTTPClient is also the base class for xbSOAPEnvelope and xbXMLDocument.
:New() -> self Create a new instance of the xbHTTPClient class.
:Reset() -> self Reinitialize object. If there is a persistent host connection open, the connection will not be closed when :Reset() is called. :Destroy() -> self Clean up any resources allocated by the client. This method must be called when a persistent connection is used and the instance is no longer required. :Execute(xURI, [cCommand], [xPostContent], [aHTTPHeaders], [xRecvFile]) -> oHTTPResponse | NIL Send a request to a remote HTTP server and receive response. If successful, the method returns a reference to an xbHTTPResponse instance containing the deserialized response returned by the remote HTTP server. If an error occurs, the method returns NIL. The cause of the error can be determined by inspecting values saved in the :ErrorCode, :ErrorMessage and :ErrorSource instance variables. Parameters: xURI The name or IP address of the remote HTTP server, including port, target resource path and query string (if any). If not specified the port defaults to 80 when using HTTP or 443 when using HTTPS. xURI may be specified as either a URL-encoded character string or an xbURI object, eg:
// option 1: using URL-encoded character string
oHttp := xbHTTPClient():new()
oHttp:Execute("http://xb2.net/login?uid=smith&pwd=%26123%2B%2B")
// option 2: using xbURI object
oURI := xbURI():new()
oURI:Scheme := "http"
oURI:Authority := "xb2.net"
oURI:Path := "login"
oURI:SetVar("uid","smith")
oURI:SetVar("pwd","&123++") // note special chars in value
oHttp := xbHTTPClient():new()
oHttp:Execute(oURI)
cCommand
Optional character string specifying the HTTP method (eg. "GET", "HEAD", "POST", "PUT",...) requested. If not
directly specified, cCommand defaults to "GET" if the xPostContent parameter is empty otherwise the
default is "POST".
xPostContent
Optional character string or object providing the HTTP request content for transmission to remote server. If an
object is provided instead of a character string, then the object must have a :AsString() method and :MimeType
property. The object's :AsString method must return the HTTP content encoded as a character string.
aHTTPHeaders
Optional array of name/value pairs representing HTTP headers to be included in the request. If provided, the array
must be in the following format:
{{cHeader1, cValue1}, {cHeader2, cValue2},... }
xRecvFile
The optional parameter xRecvFile determines how the HTTP message content is saved. If xRecvFile is provided,
then the content will be saved in a file, otherwise it will be saved in the instance variable :HTTPResponse:Content.
The file where received data is saved can be specified as either a numeric handle as returned by FOpen() or FCreate(), or as a character string denoting the file name and path. NOTE: If a file handle is provided, then received data will be saved starting at the current file pointer offset. On return, the file pointer will be positioned on the last byte written to the file. If a file name is specified instead of a numeric file handle, then the file will be closed.
Example:
oHttp := xbHTTPClient():new()
oHttp:Transport := VIA_WININET
oForm := xbForm():new()
oForm:SetVar("username", "indigo")
oForm:SetVar("password", "74Y5aU")
aHeaders := {{"Accept-Charset", "ISO-8859-1, US-ASCII"}, {"Cache-Control", "private"}}
oResp := oHttp:Execute("https://www.sterlingwebforms.com/webforms/scripts/default.asp?DisplayLang=English","POST",oForm, aHeaders)
if oResp == NIL
MsgBox("Error:" + str(oHttp:ErrorCode) + chr(10) + oHttp:ErrorMessage)
else
DispHtml(oResp:Content)
endif
:ErrorMessage() -> cErrorText
Return error description of most recent WinSock or WinInet error.
:GetPayload() -> oPayload
Perform any required payload composition and return a reference to the :Payload property.
:KeepAlive( lSet ) -> lKeepAlive
Specify .T. to create a persistent connection to a host. A persistent connection is useful when one of more
methods must be executed multiple times on the same host. Once the connection is no longer required, the
:Destroy() method must be called to release system resources that were allocated by the persistent
connection.
Example:
oHttp := xbHTTPClient():new()
oHttp:SetProxy("192.168.0.1", 8888, "robin", "batmobile1" )
// create a persistent connection since we will be
// executing multiple times on same server
oHttp:KeepAlive(.t.)
while inkey(10) != K_ESC
oResp := oHttp:Execute("http://investdb.theglobeandmail.com/invest/investSQL/gx.stock_today?pi_symbol=ibm-n")
DispHtml(oResp:Content)
end
// close persistent connection and cleanup resources
oHttp:Destroy()
:RecvTimeout([nMilliSec]) -> nTimeout
Set maximum number of millisecs to wait when receiving data from the HTTP server. The default value is zero, which
refers to an infinite timeout. Any other setting is the timeout, in milliseconds. It is valid to set the timeout
to any value, but values less than 500 milliseconds (half a second) are interpreted to be 500 milliseconds. When
nMilliSec is not specified, the method will return the current setting.
:SendTimeout([nMilliSec]) -> nTimeout
Set maximum number of millisecs to wait when sending data to HTTP server. The default value is zero, which refers
to an infinite timeout. Any other setting is the timeout, in milliseconds. It is valid to set the timeout to any
value, but values less than 500 milliseconds (half a second) are interpreted to be 500 milliseconds. When
nMilliSec is not specified, the method will return the current setting.
:SetAuthorization(cUserID, [cPassword]) -> self
This method is used to supply the user ID and password for 'basic' authentication required by some HTTP servers.
:SetCallBack([xCallBack]) -> self
Register an object or codeblock to receive callback events. If a callback has already been registered, it can be
cancelled by setting xCallBack to NIL.
For more information, please see: xbSocket:SetCallBack. :SetProxy(cProxyHost, [nProxyPort], [cUserID], [cPassword]) -> self Call this method to set the proxy used to connect to the HTTP server. Parameters: cProxyHost The name or IP address of the proxy server. cProxyPort The port number used to connect to the proxy server. If not specified, the default is 80, or 443 when an SSL context is defined. cUserID The user ID for logging into the proxy server (if required). cPassword The password for logging into the proxy server (if required). :SetSSLContext([oSSLContext]) -> self Designate an xbSSLContext object, oSSLContext to be used for secure communications with the peer. If oSSLContext is NIL or no parameter is supplied, then a current SSL/TLS connection (if there is one) will be shut down and it's corresponding xbSSLContext will be detached from this xbHTTPClient.
NOTE: The :Execute() method will automatically create a secure connection when the target URL includes an HTTPS scheme. It is only necessary to call this method when specific SSL/TLS properties need to be set (eg. client certificate, CA lists, cypher suites,...) and :Transport is set to VIA_SOCKETS (the default).
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:CertKeyword
exported/character
Specifies the search string to be used for locating a client certificate in the Windows system certificate
store. The first certificate containing the specified string (case insensitive) within it's subject field is used.
This property only applies when :Transport is set to VIA_WININET. When using the default transport method
VIA_SOCKETS, a client certificate is specified by using :SetSSLContext to attach an xbSSLContext object.
:CertUseDefault
exported/logical
When set to .T., the system will automatically send the first matching client certificate (from Windows system
certificate store) when remote HTTP server requests SSL/TLS client authentication. This property only applies when
:Transport is set to VIA_WININET. When using the default transport method VIA_SOCKETS, a client certificate
is specified by using :SetSSLContext to attach an xbSSLContext object.
:ErrorCode
exported/numeric
The WinSock or WinInet error code number.
:ErrorSource
exported/character
Additional debugging information about the last error.
:HTTPResponse
readonly/object
Reference to xbHTTPResponse object representing response returned by the remote HTTP server.
:HTTPVersion
exported/character
The HTTP protocol version of the request, eg. "1.1" or "1.0". The default is "1.1"
:MimeType
exported/character
The MIME encoding type of the HTTP request content. By default it is set to "text/plain".
:Payload
exported/object
Provides a reference to the xbPayload instance. One or more attachments may be
combined to form a single payload by using :Payload:Add(), example:
oReq := xbHTTPClient():new()
aFiles := Directory("d:\photos\*.jpg")
// attach the files
for i := 1 to len(aFiles)
oReq:Payload:Add("d:\photos\" + aFiles[i,F_NAME], PL_DATA_FILE, nil, nil, aFiles[i,F_NAME])
next
// transmit payload to HTTP server
oResp := oReq:Execute("http://www.fotostore.net/upload?uid=R034657;")
if oResp == NIL
MsgBox("An error occurred trying to send request to HTTP server!" + chr(10) +;
"Error code: " + NTrim(oReq:ErrorCode) + chr(10) + oReq:ErrorMessage )
Return .f.
endif
? "HTTP server response:"
? oResp:Content
:Transport
exported/numeric
Specifies the transport medium that will be used to deliver the HTTP request. The following options are available:
VIA_SOCKETS (the default), and VIA_WININET. The default method uses the low level WinSock library to communicate
with the HTTP server directly whereas VIA_WININET uses the higher level WinInet library.
Using WinInet can be useful when it is desirable to use the client machine's preconfigured Internet Explorer
settings such as proxy server, security settings and client certificates. When using VIA_WININET, secure SSL/TLS
connections will use the Microsoft security provider instead of OpenSSL.
:SecurityFlags
exported/numeric
Optional SSL/TLS security flags to use when :Transport is set to VIA_WININET. The following constants, defined
in Xb2NET.CH, provide a list of security flags that can be used. Individual flags can be added together to
achieve the desired security behaviour:
SECURITY_FLAG_IGNORE_REVOCATION - Ignores certificate revocation problems.
SECURITY_FLAG_IGNORE_UNKNOWN_CA - Ignores unknown certificate authority problems.
SECURITY_FLAG_IGNORE_WRONG_USAGE - Ignores incorrect usage problems.
SECURITY_FLAG_IGNORE_CERT_CN_INVALID - Ignores errors where the certificate common name (host name field) is incorrect.
SECURITY_FLAG_IGNORE_CERT_DATE_INVALID - Ignores errors where the SSL/TLS certificate date that was received from the server is bad or the certificate has expired.
SECURITY_FLAG_IGNORE_REDIRECT_TO_HTTPS - Ignores errors where the application is moving from a non-SSL/TLS to an SSL/TLS connection because of a redirect.
SECURITY_FLAG_IGNORE_REDIRECT_TO_HTTP - Ignores error where the application is moving from an SSL/TLS to an non-SSL/TLS connection because of a redirect.
:SSLContext
readonly/object
Reference to the xbSSLContext instance, or NIL if no SSL context has been assigned.
inherited from xbHTTPClient
This class provides a simplified means for generating XML requests and parsing XML responses.
:New([cXML]) -> self Create a new instance of the xbXMLDocument class and optionally parse the XML document cXML.
AddPayload( cName, xData, [nDataType], [cType], [nTypeType], [cID], [cOptions], [nPos], [cXMLAttrib] ) -> cID Attach a payload. The payload can be a disk file, a character string, an object containing an :AsString() method, or any Xbase++ variable. The method returns a character string representing the payload identifier. Parameters: cName The XML parameter name. xData The payload to attach. nDataType Optional numeric parameter indicating the data type of xData. If not provided, the payload data type will be inferred from the valtype of xData. If supplied, nDataType must be set to one of the following constants defined in Xb2NET.CH:
PL_DATA_NONE
There is no data. Attach an empty record.
PL_DATA_STRING
A literal character string.
PL_DATA_FILE
A disk file. In this case, xData can be specified as either a character string indicating the file name
(including path) or a numeric file handle as returned by FOpen().
PL_DATA_OBJECT
An object having a :AsString() method and :MimeType property. The object's :AsString method is called during
serialization with the result encoded as one payload record. A single parameter representing the payload ID is
passed to the :AsString method when evaluated. The advantage of using an object vs. a literal character string is
that the object may return dynamic content. A second advantage is better memory utilization in the case of
multiple payloads. Assuming that the object generates some large content dynamically, system memory is utilized
only when the specific payload record is serialized.
PL_DATA_CB
A codeblock whose return value is encoded as one payload record. A single parameter representing the payload ID is
passed to the codeblock during serialization. if nTypeType is set to PL_TYPE_XBASE, then the return
value of the codeblock may be any Xbase++ data type. Otherwise, the return value must be a literal
character string. The advantage of using a codeblock vs. a literal character string is that a codeblock may
return dynamic content. Another advantage is better memory utilization in the case of multiple payloads. If the
codeblock generates some large content dynamically, system memory is utilized only when the specific payload
record is serialized.
PL_DATA_XBASE
Xbase++ variable of any data type (object, codeblock, array, number, string, date, etc...). When received
by another Xb2.NET application, the payload data is converted back into the same native Xbase++ data type.
Use this type only when the payload recipient is another Xb2.NET application!
cType
An optional character string specifying the payload content type. This is either a MIME type or a URI reference. Examples:
"http://schemas.xmlsoap.org/soap/envelope/" (a URI reference)
"text/xml" (a MIME media-type)
nTypeType
Optional numeric parameter indicating the type of cType parameter. The default is PL_TYPE_UNKNOWN.
If supplied, nTypeType must be set to one of the following constants defined in Xb2NET.CH:
PL_TYPE_MIME
cType is a MIME media-type, eg: "audio/mpeg"
PL_TYPE_URI
cType is an absolute URI. URIs can be used for message types that are not expected to be registered as
media types or that do not map well onto the media type mechanism, eg: http://schemas.xmlsoap.org/rp/
PL_TYPE_UNKNOWN
The type is not known. This is the default.
PL_TYPE_NONE
There is no data. Attach an empty record.
PL_TYPE_XBASE
xData contains an Xbase++ value of any data type (object, codeblock, array, number, string, date,
etc...). When received by another Xb2.NET application, the payload data is converted back into the same native
Xbase++ data type. Use this type only when the payload recipient is another Xb2.NET application!
cID
Optional character string specifying a payload identifier. If not provided, a unique system generated ID will be
used instead. This is the same ID value returned by the :AddPayload() method.
cOptions
Optional character string providing additional payload information that may be useful to the receiver.
nPos
Optional integer numeric value specifying the position of this payload relative to previously attached payloads.
If not specified, the payload is appended to the previous payloads. To make this the first payload item, set
nPos to 1.
cXMLAttrib
Optional character string allowing special XML tag attributes to be included with this XML parameter.
AddVar(cName, xValue, [cXMLAttrib])
Add a new variable cName, value xValue and optional XML attribute cXMLAttrib to the XML
document. Unlike :SetVar, this method does not check if another element with name cName already
exists in the XML document. It is therefore possible to add multiple elements with the same name.
:AsString() -> cXML
Serialize object into XML document.
:Execute(xURI, [cXMLStream], [aHTTPHeaders], [xRecvFile]) -> oXMLReply | oHTTPResponse | NIL
Send an XML request to a remote HTTP server and receive response. If successful, the method returns a reference to
either an xbHTTPResponse instance or an xbXMLDocument instance providing the deserialized response returned by
the remote HTTP server. If an error occurs, the method returns NIL. The cause of the error can be determined by
inspecting values saved in the :ErrorCode, :ErrorMessage and :ErrorSource instance variables.
The method returns an xbHTTPResponse rather that an xbXMLDocument instance under the following conditions: (1)
Response content is directed to a file (xRecvFile parameter is provided), or (2)
:DeserializeResponse property is set ot .F.
Parameters:
xURI
The name or IP address of the remote HTTP server, including port, target resource path and query string (if
any). If not specified the port defaults to 80 when using HTTP or 443 when using HTTPS. xURI may be
specified as either a URL-encoded character string or an xbURI object. Please see
xbHTTPClient:Execute for an example.:
cXMLStream
An optional parameter that can be used to provide a pre-serialized XML document which will be transmitted to the
server as is. Since the serialized envelope is already provided, it it not necessary to use :SetVar or
:AddVar to define the XML document.
aHTTPHeaders
Optional array of name/value pairs representing HTTP headers to be included in the request. If provided, the array
must be in the following format:
{{cHeader1, cValue1}, {cHeader2, cValue2},... }
xRecvFile
The optional parameter xRecvFile determines how the response content is saved. If xRecvFile is provided,
then the content will be saved in a file, otherwise it will be saved in the instance variable :HTTPResponse:Content.
The file where received data is saved can be specified as either a numeric handle as returned by FOpen() or FCreate(), or as a character string denoting the file name and path. NOTE: If a file handle is provided, then received data will be saved starting at the current file pointer offset. On return, the file pointer will be positioned on the last byte written to the file. If a file name is specified instead of a numeric file handle, then the file will be closed.
If this parameter is provided, then the response sent by the HTTP server will not be deserialized. In this case the :Execute method will return a reference to an xbHTTPResponse object.
Example:
oXml := xbXMLDocument():new()
oReq := xbComplexType():new("FDXRateRequest")
oXml:AddVar("FDXRateRequest", oReq)
oHeader := xbComplexType():New("RequestHeader")
oHeader:AddVar("CustomerTransactionIdentifier", xbCreateGuid())
oHeader:AddVar("AccountNumber", "1273092")
oHeader:AddVar("MeterNumber", "74821")
oHeader:AddVar("CarrierCode", "FDXE")
oReq:AddVar("RequestHeader", oHeader)
oReq:AddVar("ShipDate", date())
oReq:AddVar("DropoffType", "REGULARPICKUP")
oReq:AddVar("Service", "PRIORITYOVERNIGHT")
oReq:AddVar("Packaging", "YOURPACKAGING")
oReq:AddVar("WeightUnits", "LBS")
oReq:AddVar("Weight", 10.0)
oReq:AddVar("OriginAddress", FdxAddress("OriginAddress", "TX", 73301, "US"))
oReq:AddVar("DestinationAddress", FdxAddress("DestinationAddress", "TN", 37115, "US"))
oReq:AddVar("Dimensions", FdxDimensions(100,35,20,"CM"))
oReq:AddVar("PackageCount", 1)
oResponse := oXml:Execute("https://gateway.fedex.com")
if oResponse == NIL
? "Error:", oXml:ErrorCode
? oXml:ErrorSource
? oXml:ErrorMessage
else
? "NetCharges:", oResponse:GetVar({"EstimatedCharges","DiscountedCharges","NetCharge"})
endif
:GetVar([acName]) -> xValue | aVarList | NIL
Retrieve a XML element by name. The parameter acName can be used in three ways:
If cName is NIL, then the method will return an array listing all XML tags as name/value pairs.
If the parameter is a simple string, then the top-level XML document is scanned for an element with the provided name. If none is found, the method returns NIL, otherwise the method returns the element's contents.
If the parameter is an array of strings representing a search path, then the XML document is searched using the provided path. If there is no match, the method returns NIL, otherwise the final element's contents are returned.
Example:
TEXT INTO cXmlDoc TRIMMED
<?xml version="1.0" ?>
<FDXRateReply xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<EstimatedCharges>
<RateScale>01552</RateScale>
<RateZone>5</RateZone>
<CurrencyCode>USD</CurrencyCode>
<BilledWeight>10.0</BilledWeight>
<DiscountedCharges>
<BaseCharge>47.75</BaseCharge>
<TotalDiscount>0.00</TotalDiscount>
<Surcharges>
<Fuel>2.63</Fuel>
<Other>0.00</Other>
</Surcharges>
<TotalSurcharge>2.63</TotalSurcharge>
<NetCharge>50.38</NetCharge>
<TotalRebate>0.00</TotalRebate>
</DiscountedCharges>
</EstimatedCharges>
</FDXRateReply>
ENDTEXT
oXml := xbXMLDocument():new(cXmlDoc)
? oXml:GetVar()
// output: {{FDXRateReply, xbComplexType, xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"}}
? oXml:GetVar("FDXRateReply")
// output: xbComplexType
? oXml:GetVar("EstimatedCharges")
// output: NIL
? oXml:GetVar({"FDXRateReply","EstimatedCharges","DiscountedCharges","NetCharge"})
// output: 50.38
:GetVarAttrib(cName) -> cAttribute | NIL
Retrieve a XML element's attributes. If the cName does not exist, the method returns NIL.
:Parse(cXML) -> self
Parse the XML document cXML. Once parsed, elements can be accessed using :GetVar.
:SetVar([xName], [xValue], [cXMLAttrib]) -> xPreviousValue | aPreviousVarList
Assign the value xValue to the parameter xName. This method and can be used is several
ways:
When xName and xValue are both NIL then delete all XML elements
When xValue is NIL, then remove the element xName
When xName is an array, replace all XML elements with the passed array of name/value pairs
Otherwise add or replace the value of an individual element xName.
The optional parameter cXMLAttrib allows custom attributes to be included within the XML element.
Examples:
// this is the default when using XML_BINDING_ENCODED format:
// <age xsi:type="xs:int">35</age>
oSoap:SetVar("age",35)
// remove attribute:
// <age >35</age>
oSoap:SetVar("age",35,'')
// add your own attribute:
// <age s0="tinyint">35</age>
oSoap:SetVar("age",35,'s0="tinyint"')
:CharacterEncoding
exported/character
The character encoding format used within XML document. Character encodings can be specified directly either within the XML
header (using :CharacterEncoding) or within the HTTP content-type header (using :MimeType). If both properties
are used to provide the character encoding format, they should match.
Example:
oXml:CharacterEncoding := "iso-8859-1"
/* produces an XML document with following header */
<?xml version="1.0" encoding="iso-8859-1" ?>
:DeserializeResponse
exported/logical
Determines whether the content returned by the remote HTTP server is parsed into an XML array. The default
behaviour is to parse the response, however this can be disabled by setting this property to .F. When disabled,
the :Execute method will return a reference to an xbHTTPResponse object rather
than a reference to a response xbXMLDocument instance.
:MimeType
exported/character
The MIME encoding type. By default it is set to "text/xml".
NOTE: If not explicitly specified, some HTTP servers will assume that the XML document is encoded using the UTF-8 charset. A conversion problem will result on the remote server when the XML document contains ASCII characters > 127. This problem can be eliminated by specifying the codepage directly using the :MimeType property.
Example:
oXml := xbXMLDocument():new()
oXml:MimeType := "text/xml; charset=windows-1252"
oXml:SetVar(...)
oXml:Execute(...)
:SerializationFormat
exported/numeric
Determines how data is serialized in the XML document for transport. The following options are possible:
XML_BINDING_ENCODED
Embed data type attributes within the XML document.
XML_BINDING_LITERAL (the default)
Do NOT include data type attributes within the XML document. This serialization format results in smaller XML documents.
:XMLArray
exported/array
A reference to the root element containing an array of the parsed XML document.
inherited from xbHTTPClient
SOAP (Simple Object Access Protocol) provides a simple and lightweight mechanism for exchanging structured and typed information between peers in a decentralized, distributed environment using XML. SOAP is an open standard developed by the W3C that can be used in a distributed environment to execute platform and application independent remote procedure calls (RPC).
:New([cSOAPEnvelope]) -> self Create a new instance of the xbSOAPEnvelope class and optionally parse the SOAP envelope cSOAPEnvelope in order to retrieve the action and attached parameters.
:AddNameSpace(cNameSpace) -> self Add an XML namespace to the SOAP envelope tag. The method can be called repeatedly to add additional namespaces.
Example:
oSoap:AddNameSpace('s0="https://www.lifeline.nl/schemas/vz33/"')
/* will produce the following SOAP Envelope tag (the elements in blue are the standard namespaces) */
<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:enc="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:s0="https://www.lifeline.nl/schemas/vz33/"
env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
AddPayload( cName, xData, [nDataType], [cType], [nTypeType], [cID], [cOptions], [nPos], [cXMLAttrib] ) -> cID
Attach a payload. The payload can be a disk file, a character string, an object containing an :AsString() method,
or any Xbase++ variable. The method returns a character string representing the payload identifier.
Parameters:
cName
The SOAP parameter name.
xData
The payload to attach.
nDataType
Optional numeric parameter indicating the data type of xData. If not provided, the payload data type will
be inferred from the valtype of xData. If supplied, nDataType must be set to one of the following
constants defined in Xb2NET.CH:
PL_DATA_NONE
There is no data. Attach an empty record.
PL_DATA_STRING
A literal character string.
PL_DATA_FILE
A disk file. In this case, xData can be specified as either a character string indicating the file name
(including path) or a numeric file handle as returned by FOpen().
PL_DATA_OBJECT
An object having a :AsString() method and :MimeType property. The object's :AsString method is called during
serialization with the result encoded as one payload record. A single parameter representing the payload ID is
passed to the :AsString method when evaluated. The advantage of using an object vs. a literal character string is
that the object may return dynamic content. A second advantage is better memory utilization in the case of
multiple payloads. Assuming that the object generates some large content dynamically, system memory is utilized
only when the specific payload record is serialized.
PL_DATA_CB
A codeblock whose return value is encoded as one payload record. A single parameter representing the payload ID is
passed to the codeblock during serialization. if nTypeType is set to PL_TYPE_XBASE, then the return
value of the codeblock may be any Xbase++ data type. Otherwise, the return value must be a literal
character string. The advantage of using a codeblock vs. a literal character string is that a codeblock may
return dynamic content. Another advantage is better memory utilization in the case of multiple payloads. If the
codeblock generates some large content dynamically, system memory is utilized only when the specific payload
record is serialized.
PL_DATA_XBASE
Xbase++ variable of any data type (object, codeblock, array, number, string, date, etc...). When received
by another Xb2.NET application, the payload data is converted back into the same native Xbase++ data type.
Use this type only when the payload recipient is another Xb2.NET application!
cType
An optional character string specifying the payload content type. This is either a MIME type or a URI reference. Examples:
"http://schemas.xmlsoap.org/soap/envelope/" (a URI reference)
"text/xml" (a MIME media-type)
nTypeType
Optional numeric parameter indicating the type of cType parameter. The default is PL_TYPE_UNKNOWN.
If supplied, nTypeType must be set to one of the following constants defined in Xb2NET.CH:
PL_TYPE_MIME
cType is a MIME media-type, eg: "audio/mpeg"
PL_TYPE_URI
cType is an absolute URI. URIs can be used for message types that are not expected to be registered as
media types or that do not map well onto the media type mechanism, eg: http://schemas.xmlsoap.org/rp/
PL_TYPE_UNKNOWN
The type is not known. This is the default.
PL_TYPE_NONE
There is no data. Attach an empty record.
PL_TYPE_XBASE
xData contains an Xbase++ value of any data type (object, codeblock, array, number, string, date,
etc...). When received by another Xb2.NET application, the payload data is converted back into the same native
Xbase++ data type. Use this type only when the payload recipient is another Xb2.NET application!
cID
Optional character string specifying a payload identifier. If not provided, a unique system generated ID will be
used instead. This is the same ID value returned by the :AddPayload() method.
cOptions
Optional character string providing additional payload information that may be useful to the receiver.
nPos
Optional integer numeric value specifying the position of this payload relative to previously attached payloads.
If not specified, the payload is appended to the previous payloads. To make this the first payload item, set
nPos to 1.
cXMLAttrib
Optional character string allowing special XML tag attributes to be included with this SOAP parameter.
AddVar(cName, xValue, [cXMLAttrib])
Add a new variable cName, value xValue and optional XML attribute cXMLAttrib to the SOAP body.
This method does not check if an element with name cName already exists in the SOAP body like :SetVar.
It is therefore possible to add multiple elements with the same name.
:AsString() -> cSOAPEnvelope
Combine the action and parameters into an XML SOAP envelope.
:GetVar([cName]) -> xValue | aVarList | NIL
Retrieve a SOAP parameter by name. If cName is NIL, then the method will return an array listing all
parameters as name/value pairs.
:GetVar([acName]) -> xValue | aVarList | NIL
Retrieve a SOAP parameter by name. The parameter acName can be used in three ways:
If cName is NIL, then the method will return an array listing all SOAP parameters as name/value pairs.
If the parameter is a simple string, then the top-level XML document is scanned for an element with the provided name. If none is found, the method returns NIL, otherwise the method returns the element's contents.
If the SOAP envelope contains a hierarchy of complex data types, then an array of strings representing a search path can be supplied for acName. If there is no match, the method returns NIL, otherwise the final element's value is returned.
Example:
see: xbXMLDocument:GetVar()
:GetVarAttrib(cName) -> cAttribute | NIL
Retrieve a SOAP parameter's XML attributes. If the cName does not exist, the method returns NIL.
:Parse(cSOAPEnvelope) -> self
Parse the SOAP envelope cSOAPEnvelope in order to retrieve the action and attached parameters. Once
parsed, the attached parameters can be accessed using :GetVar.
:SetFault([cFaultCode],[cFaultString],[cFaultActor],[cDetailCode],[cDetailString]) -> cFaultEnvelope
Generate a SOAP fault envelope. Calling this method will clear the action and all parameters.
Parameters:
cFaultCode
A character string that is intended for use by software to provide an algorithmic mechanism for identifying
the fault. The following is the set of faultcodes defined by the "http://schemas.xmlsoap.org/soap/envelope/"
namespace: VersionMismatch, MustUnderstand, Client, Server. If not specified, the default is
"Server".
cFaultString
A string intended to provide a human readable explanation of the fault. It should provide some information
explaining the nature of the fault. If not specified, the default is "Server Error".
cFaultActor
A URI character string providing information about who caused the fault to happen within the message path.
cDetailCode
A character string that can be used used to provide an application specific error code related to the body of
the SOAP message. The detailcode is intended for use by software to provide an algorithmic mechanism for
identifying the fault.
cDetailString
A character string that can be used to provide application specific error information related to the body of
the SOAP message. The detailstring is intended to provide a human readable explanation of the fault.
:SetStyle([nMessageStyle], [nSerializationFormat]) -> self
This method sets the formatting style of the SOAP envelope. All parameters are optional.
Parameters:
nMessageStyle
Determines whether message is formatted using RPC or document style. The following options are possible:
SOAP_STYLE_RPC (the default)
RPC style implies that the SOAP Body contains an element with the name of the method or remote procedure
being invoked. This element in turn contains an element for each parameter of that procedure.
SOAP_STYLE_DOCUMENT
Document style implies that the SOAP Body contains one or more child elements called parts. There are no
SOAP formatting rules for what the Body contains; it contains whatever the sender and the receiver agree
upon.
nSerializationFormat Determines how data is serialized in the SOAP envelope for transport. The following options are possible:
SOAP_BINDING_ENCODED
Uses the SOAP encoding rules defined in section 5 of SOAP 1.1. When using this format, data type information is
embedded within the SOAP envelope for each parameter. This is the default when SOAP_STYLE_RPC is selected.
SOAP_BINDING_LITERAL
Data is serialized according to a schema. In practice, this schema is usually expressed using W3C XML Schema. When
using this format, data type information and XML attributes are NOT embedded within the SOAP envelope resulting in
smaller envelopes. This is the default when SOAP_STYLE_DOCUMENT is selected.
:SetVar([xName], [xValue], [cXMLAttrib]) -> xPreviousValue | aPreviousVarList
Assign the value xValue to the parameter xName. This method and can be used is several
ways:
When xName and xValue are both NIL then delete all SOAP parameters
When xValue is NIL, then remove the parameter xName
When xName is an array, replace all SOAP parameters with the passed array of name/value pairs
Otherwise add or replace the value of an individual parameter xName.
The optional parameter cXMLAttrib allows custom XML tag attributes to be included with the SOAP parameter.
Examples:
// this is the default when using SOAP_BINDING_ENCODED format:
// <age xsi:type="xs:int">35</age>
oSoap:SetVar("age",35)
// remove attribute:
// <age >35</age>
oSoap:SetVar("age",35,'')
// add your own attribute:
// <age s0="tinyint">35</age>
oSoap:SetVar("age",35,'s0="tinyint"')
Client-Side Only Methods
(see additional methods in parent xbHTTPClient class)
:Execute(xURI, [cMethod], [cSOAPAction], [cXMLStream]) -> oSOAPReply
Execute a method on a remote SOAP server. The method returns an xbSOAPEnvelope object that will contain data
returned by the remote SOAP server, or a fault if the method failed to execute.
Parameters:
xURI
The name or IP address of the remote SOAP server, including port, target resource path and query string (if
any). If not specified the port defaults to 80 when using HTTP or 443 when using HTTPS. xURI may be
specified as either a URL-encoded character string or an xbURI object. Please see
xbHTTPClient:Execute for an example.:
cMethod
The requested action to execute on the server. If not specified cMethod defaults to :Action, in
which case :Action must not be blank.
cSOAPAction
An optional parameter that will set the SOAPAction header field in the HTTP request. If not specified
cSOAPAction defaults to cMethod. Some SOAP servers may require a specific SOAPAction header
field to be specified.
cXMLStream
An optional parameter that can be used to provide a pre-serialized XML SOAP envelope which will be transmitted
to the server as is. Since the serialized envelope is already provided, it it not necessary to use :SetVar,
:SetStyle, :AddNameSpace, and :NameSpace to define the SOAP message.
Example:
oAgent := xbSOAPEnvelope():new()
oAgent:NameSpace := "urn:xmethods-CurrencyExchange"
oAgent:SetVar("Country1", "USA" )
oAgent:SetVar("Country2", "EURO")
// Execute request
oResult := oAgent:Execute("http://services.xmethods.net:80/soap", "getRate")
// Print exchange rate
? oResult:GetVar("Result")
:Action
exported/character
The name of the SOAP action or method contained within the Body of the SOAP envelope. All SOAP
envelopes must have an action defined.
:ActionNode
exported/array
A reference to the array containing the method or action node within the :XMLArray array.
:CharacterEncoding
exported/character
The character encoding format used within XML document. Character encodings can be specified directly either within the XML
header (using :CharacterEncoding) or within the HTTP content-type header (using :MimeType). If both properties
are used to provide the character encoding format, they should match.
Example:
oSoap:CharacterEncoding := "iso-8859-1"
/* produces a SOAP Envelope with following XML header */
<?xml version="1.0" encoding="iso-8859-1" ?>
:Header
exported/character
The SOAP envelope header. The Header is an optional element that may be present in a SOAP message.
If present, the element is the first immediate child element of a SOAP envelope (it is not part of the SOAP Body). Eg:
oSoap:Header := '<AuthHeader xmlns="http://ups.com/ShippingServer"><AuthToken>xYu0r28v6</AuthToken></AuthHeader>'
:HeaderNode
exported/array
A reference to the array containing the Header node within the :XMLArray array.
:MessageStyle
exported/numeric
Determines whether message is formatted using RPC or document style. The following options are possible:
SOAP_STYLE_RPC (the default)
RPC style implies that the SOAP Body contains an element with the name of the method or remote procedure
being invoked. This element in turn contains an element for each parameter of that procedure.
SOAP_STYLE_DOCUMENT
Document style implies that the SOAP Body contains one or more child elements called parts. There are no
SOAP formatting rules for what the Body contains; it contains whatever the sender and the receiver agree
upon.
:MimeType
exported/character
The MIME encoding type. By default it is set to "text/xml".
NOTE: If not explicitly specified, some SOAP servers (eg. Microsoft ASP .NET server) will assume that the XML SOAP message is encoded using the UTF-8 charset. A conversion problem will result on the remote server when the SOAP data contains ASCII characters > 127. This problem can be eliminated by specifying the codepage directly using the :MimeType property.
Example:
oSoap := xbSOAPEnvelope():new()
oSoap:MimeType := "text/xml; charset=windows-1252"
oSoap:SetVar(...)
oSoap:Execute(...)
:NameSpace
exported/character
This is the namespace of the SOAP method. Some SOAP servers require a particular namespace to be specified when
executing a method. The default is "http://xb2.net/soap".
:Version
exported/character
The SOAP specification version number used to generate SOAP message structures and message exchange patterns.
Among other things, this property determines the message MIME encoding type and document namespaces used within
the SOAP envelope. Two versions are supported: "1.1" and "1.2". The default is "1.1".
:XMLArray
exported/array
A reference to the root element containing an array of the parsed XML SOAP envelope.
The xbComplexType class is used to represent complex data structures. Data structures can be nested, and may contain any other type, including an array. Instances of xbComplexType are typically used by the xbSOAPEnvelope and xbXMLDocument classes to serialize and deserialize complex data structures.
:New([cName], [xAttrib], [oPayload]) -> self Create a new instance of the xbComplexType class. Parameters: cName The name of the complex type. If not supplied, the default is "Struct". xAttrib Optional attribute associated with the complex type. When the complex type is used in a a SOAP envelope, xAttrib must be a character string that represents the complex type's XML attributes. oPayload This parameter is optional, if supplied it provides a reference to an xbPayload object to be used by :AddPayload().
Example:
// set carton dimensions
oDim := xbComplexType():new("Dimensions")
oDim:SetVar("Length", nLen)
oDim:SetVar("Width" , nWidth)
oDim:SetVar("Height", nHeight)
oDim:SetVar("Units" , cUnits)
// define carton
oCarton := xbComplexType():New("carton")
oCarton:SetVar("Dimensions", oDim)
oCarton:SetVar("orderNumber", cHostOrder)
oCarton:SetVar("amount", nPrice)
oCarton:SetVar("weight", nWeight)
oCarton:SetVar("printerAddress", cTargetPrinter)
oCarton:SetVar("toteId", cTotLabel)
// call shipping system to rate package
oSoap := xbSOAPEnvelope():New()
oSoap:MimeType := "text/xml; charset=windows-1252"
oSoap:SetStyle(SOAP_STYLE_DOCUMENT)
oSoap:NameSpace := "http://www.xyzco.com/webservices/"
oSoap:SetVar("carton", oCarton)
oRet := oSoap:Execute("http://192.168.2.23","rateCarton","http://www.xyzco.com/webservices/rateCarton")
lSuccess := oRet:GetVar("rateCartonResult") == "1"
:AddPayload( cName, xData, [nDataType], [cType], [nTypeType], [cID], [cOptions], [nPos], [cXMLAttrib] ) -> cID Attach a payload. The payload can be a disk file, a character string, an object containing an :AsString() method, or any Xbase++ variable. The method returns a character string representing the payload identifier.
Note: An error will be raised if this method is used prior to providing a reference to the target xbPayload object. The target xbPayload object may be specified as a parameter to the object init method, or assigned to the :Payload instance variable. Parameters: cName The XML parameter name. xData The payload to attach. nDataType Optional numeric parameter indicating the data type of xData. If not provided, the payload data type will be inferred from the valtype of xData. If supplied, nDataType must be set to one of the following constants defined in Xb2NET.CH:
PL_DATA_NONE
There is no data. Attach an empty record.
PL_DATA_STRING
A literal character string.
PL_DATA_FILE
A disk file. In this case, xData can be specified as either a character string indicating the file name
(including path) or a numeric file handle as returned by FOpen().
PL_DATA_OBJECT
An object having a :AsString() method and :MimeType property. The object's :AsString method is called during
serialization with the result encoded as one payload record. A single parameter representing the payload ID is
passed to the :AsString method when evaluated. The advantage of using an object vs. a literal character string is
that the object may return dynamic content. A second advantage is better memory utilization in the case of
multiple payloads. Assuming that the object generates some large content dynamically, system memory is utilized
only when the specific payload record is serialized.
PL_DATA_CB
A codeblock whose return value is encoded as one payload record. A single parameter representing the payload ID is
passed to the codeblock during serialization. if nTypeType is set to PL_TYPE_XBASE, then the return
value of the codeblock may be any Xbase++ data type. Otherwise, the return value must be a literal
character string. The advantage of using a codeblock vs. a literal character string is that a codeblock may
return dynamic content. Another advantage is better memory utilization in the case of multiple payloads. If the
codeblock generates some large content dynamically, system memory is utilized only when the specific payload
record is serialized.
PL_DATA_XBASE
Xbase++ variable of any data type (object, codeblock, array, number, string, date, etc...). When received
by another Xb2.NET application, the payload data is converted back into the same native Xbase++ data type.
Use this type only when the payload recipient is another Xb2.NET application!
cType
An optional character string specifying the payload content type. This is either a MIME type or a URI reference. Examples:
"http://schemas.xmlsoap.org/soap/envelope/" (a URI reference)
"text/xml" (a MIME media-type)
nTypeType
Optional numeric parameter indicating the type of cType parameter. The default is PL_TYPE_UNKNOWN.
If supplied, nTypeType must be set to one of the following constants defined in Xb2NET.CH:
PL_TYPE_MIME
cType is a MIME media-type, eg: "audio/mpeg"
PL_TYPE_URI
cType is an absolute URI. URIs can be used for message types that are not expected to be registered as
media types or that do not map well onto the media type mechanism, eg: http://schemas.xmlsoap.org/rp/
PL_TYPE_UNKNOWN
The type is not known. This is the default.
PL_TYPE_NONE
There is no data. Attach an empty record.
PL_TYPE_XBASE
xData contains an Xbase++ value of any data type (object, codeblock, array, number, string, date,
etc...). When received by another Xb2.NET application, the payload data is converted back into the same native
Xbase++ data type. Use this type only when the payload recipient is another Xb2.NET application!
cID
Optional character string specifying a payload identifier. If not provided, a unique system generated ID will be
used instead. This is the same ID value returned by the :AddPayload() method.
cOptions
Optional character string providing additional payload information that may be useful to the receiver.
nPos
Optional integer numeric value specifying the position of this payload relative to previously attached payloads.
If not specified, the payload is appended to the previous payloads. To make this the first payload item, set
nPos to 1.
cXMLAttrib
Optional character string allowing special XML tag attributes to be included with this XML parameter.
Example:
// initialize SOAP envelope object
oSoap := xbSOAPEnvelope():new()
oSoap:SetStyle(SOAP_STYLE_DOCUMENT)
oSoap:Payload:SetFormat(PAYLOAD_MTOM)
// create "request" structure and provide reference to SOAP payload
oReq := xbComplexType():New()
oReq:Payload := oSoap:Payload
oReq:AddVar("EmailAddress", "test@gmail.com")
oReq:AddVar("FileName", "upload.txt")
oReq:AddPayload("FileData", "c:\upload\upload.txt", PL_DATA_FILE)
// add "request" structure to SOAP envelope
oSoap:AddVar("Request", oReq)
oResult := oSoap:Execute("http://live.xb2.net","EchoAll")
:AddVar(cName, xValue, [xAttrib])
Add a new variable xName, value xValue and optional attribute xAttrib to the data structure.
This method does not check if the element with name cName already exists in the structure. It is therefore
possible to add multiple elements with the same name.
:GetVar([acName]) -> xValue | aVarList | NIL
Search the data structure and retrieve the first element's value matching acName. The parameter
acName can be used in three ways:
If cName is NIL, then the method will return an array listing all elements as subarrays of {cName, xValue, xAttrib}.
If the parameter is a simple string, then the data structure is scanned for an element with the provided name. If none is found, the method returns NIL, otherwise the method returns the element's contents.
If the data structure contains a hierarchy of complex data types, then an array of strings representing a search path can be supplied for acName. If there is no match, the method returns NIL, otherwise the final element's value is returned.
Example:
see: xbXMLDocument:GetVar()
:GetVarAttrib(cName) -> cAttribute | NIL
Retrieve an element's attribute. If the cName does not exist, the method returns NIL.
:Reset([cName], [xAttrib]) -> self
Reinitialize object. For parameter information see :New().
:SetVar([xName], [xValue], [xAttrib]) -> xPreviousValue | aPreviousVarList
Assign the value xValue and optional attribute xAttrib to the first element with name xName.
This method and can be used is several ways:
When xName and xValue are both NIL then empty the data structure.
When xValue is NIL, then delete the first element with name xName.
When xName is an array; replace the entire data structure with the passed array of {cName, xValue, xAttrib} elements.
Otherwise add or replace the value of an individual element xName.
:Attrib
exported/any data type
Optional attribute associated with the complex type. When the complex type is used in a SOAP envelope,
:Attrib must be a character string that represents the complex type's XML attributes.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:Name
exported/character
The name of the complex type.
:Payload
exported/object
Provides a reference to an optional xbPayload object.
:VarList
exported/array
The data structure represented as an array of elements with the following format:
{{cName1, xValue1, xAttrib1}, {cName2, xValue2, xAttrib2},... }
A Form is typically used by a client application in conjunction with an HTTP-POST method to send data to the server. It consists of name=value pairs encoded so that the form can be reliably disassembled into it's individual components at the server end.
:New([cEncodedFormString]) -> self Create a new instance of the xbForm class and optionally parse an encoded form cEncodedFormString in order to retrieve the attached variables and data.
Example:
oHttp := xbHTTPClient():new()
oHttp:Transport := VIA_WININET
oForm := xbForm():new()
oForm:SetVar("Action", "VIEW")
oForm:SetVar("FormID", cDocumentID)
oResp := oHttp:Execute("https://www.sterlingwebforms.com/webforms/scripts/inbox.asp",,oForm)
if oResp == NIL
MsgBox("Error:" + str(oHttp:ErrorCode) + chr(10) + oHttp:ErrorMessage)
else
DispHtml(oResp:Content)
endif
:AsString() -> cEncodedFormString Encode the form variables and data suitable for safe HTTP transport. :GetVar([cName]) -> xValue | aVarList | NIL Retrieve a form variable. If cName is NIL, then the method will return an array listing all form variables as name/value pairs. :Parse(cEncodedFormString) -> self Parse an encoded form cEncodedFormString, to separate the attached variables which can later be accessed using :GetVar. :Reset() -> self Reinitialize object. :SetVar([xName], [cValue]) -> xPreviousValue | aPreviousVarList Assign the value cValue to the form variable xName. This method and can be used is several ways:
When xName and cValue are both NIL then delete all form variables
When cValue is NIL, then remove the form variable xName
When xName is an array, replace all form variables with the passed array of name/value pairs
Otherwise add or replace the value of an individual form variable xName.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:MimeType
exported/character
The MIME encoding type. It is set to: "application/x-www-form-urlencoded"
FTP (File Transfer Protocol) client provides methods for managing directories and files on a remote FTP or FTPS server. The class is fully compliant with RFC-959, RFC-2228 and RFC-4217. It provides support for AUTH TLS, AUTH SSL and Implicit SSL connections for control and data connections.
:New([oSSLContext]) -> self Create a new instance of the xbFTPClient class. The optional parameter oSSLContext can be set to an instance of the xbSSLContext class in order to make the connection secure.
NOTE: The :Connect method will automatically create a secure connection when the target URL includes an FTPS scheme. The oSSLContext parameter is only needed when specific SSL/TLS properties need to be set (eg. client certificate, CA lists, cypher suites,...).
Example:
oFtp := xbFTPClient():new()
if ! oFtp:Connect("ftps://thebatcave.com:1939")
MsgBox("Failed to connect to FTP server!")
Return
endif
if oFtp:Login("batman", "6otHam825")
oFtp:GetFile("thejoker.doc")
else
MsgBox("Login failed!")
endif
oFtp:Destroy()
Configuration / Life Cycle :Connect(xHostAddress, [nPort]) -> lSuccess Establish connection with FTP server. The method returns .T. if the connection was successfully established. Parameters: xHostAddress The address of the remote FTP server. It can be specified either as a numeric address in network byte order, an IP address in form of a dotted octet string (ex. 127.0.0.1) or a host name. In addition, the host, port and scheme (ftp or ftps) can be combined in standard URL format, eg: ftp://undergroundgarage.org:21. nPort The numeric port number of the remote FTP server. If not directly specified, the default port is 21 for FTP and 990 for FTPS when :ImplicitSSL is set to .T. :Close() -> self Logout from FTP server and close all connections. :Destroy() -> self Logout from FTP server, close all connections and release any system resources used by object. :RecvTimeout([nMilliSec]) -> nTimeout Set maximum number of millisecs to wait when receiving data from the FTP server. The default value is zero, which refers to an infinite timeout. Any other setting is the timeout, in milliseconds. It is valid to set the timeout to any value, but values less than 500 milliseconds (half a second) are interpreted to be 500 milliseconds. When nMilliSec is not specified, the method will return the current setting. :SendTimeout([nMilliSec]) -> nTimeout Set maximum number of millisecs to wait when sending data to FTP server. The default value is zero, which refers to an infinite timeout. Any other setting is the timeout, in milliseconds. It is valid to set the timeout to any value, but values less than 500 milliseconds (half a second) are interpreted to be 500 milliseconds. When nMilliSec is not specified, the method will return the current setting. :SetCallBack([xCallBack]) -> self Register an object or codeblock to receive callback events. If a callback has already been registered, it can be cancelled by setting xCallBack to NIL.
When xCallBack is provided as an object, the object must be inherited from the Xbase++ XbpPartHandler class. In this case, the xbFTPClient class will place events of type xbeP_xbFTPClient into the Xbase++ event queue. These events can be read (asynchronously) from the event queue by using the standard Xbase++ function AppEvent().
When xCallBack is provided as a codeblock, the user codeblock will be executed (synchronously) whenever an event occurs within the xbFTPClient instance. Example:
oFtp:SetCallBack( {|a,b|qout(a,b)} ) // codeblock executes synchronously
Two message parameters are provided to the AppEvent() function / user codeblock. The first parameter will be an integer numeric status code defined in Xb2NET.CH with the prefix FTP_ST_* or FTP_ERR_*, the second parameter will be a character string providing details of the event.
Example (asynchronous callback):
oDlg := XbpDialog():New(AppDeskTop(), AppDeskTop(), {50,50}, {600,400})
oDlg:Title := "FTP Status"
oDlg:create()
oMLE := XbpMLE():new()
oMLE:WordWrap := .f.
oMLE:Editable := .f.
oMLE:Create(oDlg:drawingArea,,{0,0}, oDlg:drawingArea:CurrentSize())
// the file upload is executed in a separate thread
oFtpThread := Thread():New()
oFtpThread:Start("UploadFile", cServer, cUserID, cPassword, cFileName, oMLE)
nEvent := 0
while nEvent != xbeP_Close
nEvent := AppEvent(@mp1, @mp2, @oXbp)
if nEvent == xbeP_xbFTPClient
// display FTP event in dialog window
cText := var2char(mp1) + " " + var2char(mp2) + CRLF
oMLE:Insert( Len(oMLE:GetData())+1, cText )
else
oXbp:handleEvent( nEvent, mp1, mp2 )
endif
end
FUNCTION UploadFile(cServer, cUserID, cPassword, cFileName, xCallBack)
Local oFtp, lSuccess
oFtp := xbFTPClient():new()
oFtp:SetCallBack(xCallBack)
lSuccess := oFtp:Connect(cServer) ;
.and. oFtp:Login(cUserID, cPassword) ;
.and. oFtp:PutFile(cFileName)
oFtp:Destroy()
Return lSuccess
:SetDataPort([cIPAddress], [nPort]) -> self
Allows the programmer to explicitly specify the client's IP address when using standard data transfer (when
:PassiveMode is .F.). This may be useful in cases where the server does not support passive mode and the FTP
client is behind a router-based firewall.
If the client is behind a router-based firewall, then the router must be configured to forward incoming connections on nPort to the client. If nPort is not specified or is set to 0 (zero), then the router must be configured to forward to the client all incoming connections on ports 1024 to 5000.
To clear a previously specified data port, call SetDataPort with no parameters, eg:
oFtp:SetDataPort()
Parameters:
cIPAddress
A character string representing the FTP client's IP address. This address must be visible to the FTP server.
nPort
The numeric port number where the FTP client will be listening for a data connection. If not directly specified,
the default value is 0 (zero), indicating that the client will choose a free port between 1024 and 5000.
Example:
oFtp := xbFTPClient():new()
oFtp:SetDataPort("207.17.4.88", 5900)
:SetSSLContext([oSSLContext]) -> self
Designate an xbSSLContext object, oSSLContext to be used for secure
communications with the FTP server. If oSSLContext is NIL or no parameter is supplied, then a current
SSL/TLS connection (if there is one) will be shut down and it's corresponding xbSSLContext will be detached
from this xbFTPClient.
NOTE: The :Connect() method will automatically create a secure connection when the target URL includes an FTPS scheme. It is only necessary to call this method when specific SSL/TLS properties need to be set (eg. client certificate, CA lists, cypher suites,...). :SSLConnect([oSSLContext]) -> lSuccess Initiate a SSL/TLS handshake with a connected FTP server. The client must already be connected to the server prior to calling this method. Under normal circumstances, it is not necessary to call this method for creating a secure connection since the :Connect method will do this automatically when either the target URL contains an FTPS scheme or an SSLContext is provided via :SetSSLContext.
Note that an FTP server will reset state information for a connected client after calling this method. For example, if the client was already logged in, it will be necessary to log in again.
oSSLContext is an optional parameter than can be set to an instance of the xbSSLContext class. This is only necessary if specific SSL/TLS properties need to be set, such as a client certificate, CA lists, cypher suites, etc.
The method will return .T. if an SSL/TLS connection has been successfully established with the FTP server. Otherwise, the method returns .F. FTP Control :CreateDirectory(cPath) -> lSuccess Create a new directory on the FTP server. cPath is a character string that contains the name of the directory to create. The method returns .T. if successful, or .F. otherwise. :DeleteDirectory(cPath) -> lSuccess Remove a directory path with the name cPath from the FTP server. The method returns .T. if the directory path was successfully deleted, or .F. otherwise. :DeleteFile(cFileName) -> lSuccess Remove a file with the name cFileName from the FTP server. The method returns .T. if the file was successfully deleted, or .F. otherwise. :Directory([cPath]) -> aDir | NIL Returns array of directory path information or NIL if an error occurs. The directory listing is returned as a one dimensional array of character strings with each array element representing one directory entry with file name, attributes and date/time information. :GetCurrentDirectory() -> cPath | NIL Return the current directory path as a string or NIL if an error returns. :GetFile(cRemoteFile, [xLocalFile], [cDataType], [lAppend]) -> lSuccess Download a file cRemoteFile from FTP server and save it locally with the name xLocalFile. The method returns .T. if the file was successfully retrieved. Parameters: cRemoteFile A character string name of the remote FTP server file to download. xLocalFile The file where received data is saved can be specified as either a numeric handle as returned by FOpen() or FCreate(), or as a character string denoting the file name and path. NOTE: If a file handle is provided, then received data will be written starting at the current file pointer offset (regardless of the value of lAppend). On return, the file will be left open and the file pointer will be positioned on the last byte written. If a file name is specified instead of a numeric handle, then the file will be closed. If xLocalFile is not provided, it defaults to cRemoteFile. cDataType By default, data will be received in binary mode. However, if the FTP server does not support binary transfer mode, then cDataType can be set to "A" to request data transfer in ASCII mode. Other data types supported by FTP include "I" for image (or binary), "E" for EBCDIC, and "L n" for local byte size (where n is the byte size). For additional information, please see the TYPE command in RFC959. lAppend An optional logical parameter that can be set to .T. in order to append received data to xLocalFile. When this parameter is NIL or .F., then any existing data will be overwritten. :GetResponse([nEventCode]) -> lSuccess Get response message from FTP server. This method is used in conjunction with the :SendCommand() to fetch the FTP server's response. The method returns .T. if a response was received from the FTP server, and .F. otherwise. The received response string and corresponding three-digit status code are stored in the :Response and :ResponseCode instance variables. :Login([cUserID], [cPassword], [cAccount]) -> lSuccess Login to FTP server. All parameters are optional character strings. If not supplied, the default cUserID is "anonymous", cPassword is a zero-lenght string and cAccount is "nul". :PutFile(xLocalFile, [cRemoteFile], [cDataType], [lAppend]) -> lSuccess Upload a file xLocalFile to FTP server and store it under the name cRemoteFile. The method returns .T. if the file was successfully uploaded. Parameters: xLocalFile The file to be uploaded can be specified as either a numeric handle as returned by FOpen() or FCreate(), or as a character string denoting the file name and path. NOTE: If a file handle is specified, then data will be transmitted beginning at the current file pointer offset. To transmit the entire file make sure that the file pointer is set to the beginning of the file. If a numeric file handle is provided, then it is the responsibility of the calling routine to close the file once the method returns. cRemoteFile A character string name of the file on on the remote FTP server. If cRemoteFile is not provided, it defaults to xLocalFile. cDataType By default, data will be uploaded in binary mode. However, if the FTP server does not support binary transfer mode, then cDataType can be set to "A" to request data transfer in ASCII mode. Other data types supported by FTP include "I" for image (or binary), "E" for EBCDIC, and "L n" for local byte size (where n is the byte size). For additional information, please see the TYPE command in RFC959. lAppend An optional logical parameter that can be set to .T. in order to append transmitted data to cRemoteFile. When this parameter is NIL or .F., then the remote file if it exists, will be overwritten. :RenameFile(cFileName, cNewFileName) -> lSuccess Rename a file stored on the FTP server. cFileName is the name of the file that will have its name changed on the remote server, and cNewFileName is the new name for the remote file. The method returns .T. if the file was successfully renamed. :SendCommand(cCommand) -> lSuccess Send a command to FTP server. The method returns .T. if the command was successfully transmitted to the FTP server, and .F. otherwise. This method is provided as a means of executing special FTP commands not implemented by this class.
Example:
oFtp:SendCommand("DELE index.htm")
oFtp:GetResponse()
? oFtp:Response
:SetCurrentDirectory([cPath]) -> lSuccess
Change to a different working directory on the FTP server. cPath is the name of the directory to change to
on the remote system, if it is set to NIL, the working directory will be set to the parent directory. The method
returns .T. if the working directory was successfully changed.
:Abort
exported/logical
Can be set to .T. in order to abort a data transfer that is currently in progress. The abort signal can
be set from an external thread or from a callback codeblock specified in :SetCallBack().
:BytesTransferred
exported/numeric
Current number of bytes transferred. This property is continually updated while data transfer is in progress.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:ElapsedTime
readonly/numeric
Number of seconds elapsed since start of data transfer.
:ErrorCode
exported/numeric
Most recent FTP or WinSock error code. FTP error codes are defined in Xb2NET.CH with the prefix FTP_ERR_*.
:ImplicitSSL
exported/logical
Determines how an SSL/TLS connection is established.
When set to .T., the :Connect method will automatically perform SSL/TLS negotiation during the connect phase (for control and all data connections). Although port 990 is registered with the IANA for this purpose, this method is not favoured by the IETF and is therefore not supported by many FTP servers.
The default value for this property is .F. meaning that as long as the FTP server supports it, an SSL/TLS
secure connection can be negotiated any time after a normal connection is established.
:PassiveMode
exported/logical
Determines whether the client or server initiates the data connection.
Normally, when a client connects to an FTP site, the server establishes the data connection back the client. However, if the server allows passive transfers, the client can establish the data connection. The default value for this property is .F., meaning that the client will wait for the server to establish a data connection.
Note that passive mode may be required for clients who are behind some types of router-based firewalls or
behind a gateway requiring passive transfers.
:Response
readonly/character
The reply sent by remote FTP server in response to last command.
:ResponseCode
readonly/character
A three-digit status code returned by remote FTP server in response to last command.
:SecureDataChannel
exported/logical
Controls security level on the data connection.
When set to .T. and a secure control channel is established with the FTP server, then new data channels will
also be secured. Note that a FTP server need not necessarily support secure data connections even though it
does support secure control connections. The default value for this property is .F.
:SSLContext
readonly/object
Reference to the xbSSLContext instance or NIL if no SSL context has been assigned.
:Host
readonly/character
The host name or IP address of remote FTP server.
:Port
readonly/numeric
The socket port number of remote FTP server.
Provides methods for serializing and deserializing or more attachments of any size (files, character strings, objects or any Xbase++ data) for transmission between an HTTP client and server. This class is also used by the xbSOAPEnvelope class for sending SOAP attachments.
:New() -> self Create a new instance of the xbPayload class.
Example:
function ShipRequest()
Local oConn, oSock, oPL, cChunk, oData, cSQL, cRet
oSock := xbSocket():New()
if ! oSock:Connect("192.168.2.10",2002)
oSock:destroy()
Return .f.
endif
oPL := xbPayload():New()
// specify requested function in payload
oPL:Add("ShipOrders",PL_DATA_STRING,"http://xb2.net/payload/",PL_TYPE_URI)
// attach SQL resultset
cSQL := "SELECT * FROM Orders WHERE Completed=1 AND Shipped=0"
oConn := SQLConnection():new()
oConn:driverConnect(nil,"DSN=Sales;UID=shipping;PWD=99",SQL_DRIVER_NOPROMPT)
oData := oConn:DataSet(cSQL)
oData:Execute() // fetch data
oConn:Destroy() // close database connection
oPL:Add(oData,PL_DATA_XBASE,nil,nil,nil,cSQL)
// attach invoices as PDF documents (documents are generated dynamically during transmission)
while ! oData:Eof()
oPL:Add({|cID|GenerateInvoice(cID)},,"application/pdf",PL_TYPE_MIME,oData:FieldGet("OrderID"))
oData:Skip()
end
// transmit data
oPL:ClearState()
while (cChunk := oPL:Serialize()) != NIL
if oSock:Send(cChunk) == SOCKET_ERROR
oPL:ClearState()
oSock:destroy()
Return .f.
endif
end
// all data sent, wait for response
cRet := oSock:RecvLine()
oSock:destroy()
Return cRet == "SUCCESS"
Add( xData, [nDataType], [cType], [nTypeType], [cID], [cOptions], [nPos] ) -> cID Attach a payload. The payload can be a disk file, a character string, an object containing an :AsString() method, or any Xbase++ variable. The method returns a character string representing the payload identifier. Parameters: xData The payload to attach. nDataType Optional numeric parameter indicating the data type of xData. If not provided, the payload data type will be inferred from the valtype of xData. If supplied, nDataType must be set to one of the following constants defined in Xb2NET.CH:
PL_DATA_NONE
There is no data. Attach an empty record.
PL_DATA_STRING
A literal character string.
PL_DATA_FILE
A disk file. In this case, xData can be specified as either a character string indicating the file name
(including path) or a numeric file handle as returned by FOpen().
PL_DATA_OBJECT
An object having a :AsString() method and :MimeType property. The object's :AsString method is called during
serialization with the result encoded as one payload record. A single parameter representing the payload ID is
passed to the :AsString method when evaluated. The advantage of using an object vs. a literal character string is
that the object may return dynamic content. A second advantage is better memory utilization in the case of
multiple payloads. Assuming that the object generates some large content dynamically, system memory is utilized
only when the specific payload record is serialized.
PL_DATA_CB
A codeblock whose return value is encoded as one payload record. A single parameter representing the payload ID is
passed to the codeblock during serialization. if nTypeType is set to PL_TYPE_XBASE, then the return
value of the codeblock may be any Xbase++ data type. Otherwise, the return value must be a literal
character string. The advantage of using a codeblock vs. a literal character string is that a codeblock may
return dynamic content. Another advantage is better memory utilization in the case of multiple payloads. If the
codeblock generates some large content dynamically, system memory is utilized only when the specific payload
record is serialized.
PL_DATA_XBASE
Xbase++ variable of any data type (object, codeblock, array, number, string, date, etc...). When received
by another Xb2.NET application, the payload data is converted back into the same native Xbase++ data type.
Use this type only when the payload recipient is another Xb2.NET application!
cType
An optional character string specifying the payload content type. This is either a MIME type or a URI reference. Examples:
"http://schemas.xmlsoap.org/soap/envelope/" (a URI reference)
"text/xml" (a MIME media-type)
nTypeType
Optional numeric parameter indicating the type of cType parameter. The default is PL_TYPE_UNKNOWN.
If supplied, nTypeType must be set to one of the following constants defined in Xb2NET.CH:
PL_TYPE_MIME
cType is a MIME media-type, eg: "audio/mpeg"
PL_TYPE_URI
cType is an absolute URI. URIs can be used for message types that are not expected to be registered as
media types or that do not map well onto the media type mechanism, eg: http://schemas.xmlsoap.org/rp/
PL_TYPE_UNKNOWN
The type is not known. This is the default.
PL_TYPE_NONE
There is no data. Attach an empty record.
PL_TYPE_XBASE
xData contains an Xbase++ value of any data type (object, codeblock, array, number, string, date,
etc...). When received by another Xb2.NET application, the payload data is converted back into the same native
Xbase++ data type. Use this type only when the payload recipient is another Xb2.NET application!
cID
Optional character string specifying a payload identifier. If not provided, a unique system generated ID will be
used instead. This is the same ID value returned by the :Add() method.
cOptions
Optional character string providing additional payload information that may be useful to the receiver.
nPos
Optional integer numeric value specifying the position of this payload relative to previously attached payloads.
If not specified, the payload is appended to the previous payloads. To make this the first payload item, set
nPos to 1.
:AsString() -> cSerializedPayload
Serialize the payloads as a single character string.
Warning: If the attachments are large, it is possible that this method will consume more memory than is available on the host system.
Use, :Serialize() instead to process the payloads in smaller chunks.
:ClearState() -> self
Reset serialization and deserialization state.
:Deserialize( cBuffer, [nBytes] ) -> nBytes
Deserialize a payload stream. As the payload stream is sequentially parsed, references to the payloads are saved in the :List property.
:GetPayload(xID) -> xPayload, or;
:GetVar(xID) -> xPayload
Retrieve a payload item by ID. The parameter xID represents the payload identifier and can be provided as a numeric or a
character string. A numeric value corresponds to an index within the :List array of payloads. A character string corresponds to
the PL_ID value of the desired payload.
The method returns NIL if the desired payload cannot be found. Otherwise the data type of the return value depends on the payload that was transmitted by the remote peer. For example, if the remote peer transmits a codeblock, the returned value will be a codeblock.
A data file transmitted by a remote peer may be returned as either a simple character string or as an xbStream object. Generally, if the file is larger than one :ChunkSize, then it will be saved to disk and an xbStream object will be returned providing a reference to the saved disk file. :Reset() -> self Reinitialize object and clear payload list. :Serialize() -> cPayloadChunk | NIL Serialize the payloads in successive chunks. The method returns NIL once all data has been serialized. :SetFormat(nFormat) -> self Set payload serialization format. The parameter nFormat is an integer numeric value that specifies the serialization format using a symbolic constant with prefix PAYLOAD_*. The table below provides currently supported payload formats including associated MIME Content-Types and specification reference:
| nFormat | MIME Content-Type | Reference |
|---|---|---|
| PAYLOAD_DIME | application/dime | IETF Internet-Draft. Reference: draft-nielsen-dime-02. June 17, 2002; expires December 2002 |
| PAYLOAD_MP_MIXED | multipart/mixed | RFC 2046, Section 5.1.3 |
| PAYLOAD_MP_FORMDATA | multipart/form-data | RFC 2388 |
| PAYLOAD_MP_RELATED | multipart/related | RFC 2387 |
| PAYLOAD_XOP | multipart/related; type="application/xop+xml"; startinfo="text/xml" | http://www.w3.org/TR/xop10/ |
| PAYLOAD_MTOM | multipart/related; type="application/xop+xml"; startinfo="application/soap+xml" | http://www.w3.org/TR/soap12-mtom/ |
:ChunkSize
exported/numeric
The maximum chunk size used for serializing files. The default value is 128 KB.
:Format
readonly/numeric
The payload serialization format. To change the serialization format, use :SetFormat() method.
:List
exported/array
Provides a reference to a two dimensional array containing information about the payloads.
The array columns can be identified using the following symbolic constants defined in Xb2NET.CH:
PL_ID
A character string containing the payload ID.
PL_DATA
The payload data; character string, object or file name.
PL_DATA_T
An integer indicating the data type of PL_DATA. The value is a reference to the symbolic constants with prefix PL_DATA_*.
PL_TYPE
A character string specifying the media-type or absolute-URI of payload.
PL_TYPE_T
An integer indicating the data type of PL_TYPE. The value is a reference to the symbolic constants with prefix PL_TYPE_*.
PL_OPTIONS
Character string providing optional information used by parser.
:MimeType
exported/character
The MIME encoding type. The default value is "application/dime".
Provides a context for implementing secure network communications using the OpenSSL library. Once initialized, an xbSSLContext object can be attached to an xbSocket, xbServer, xbHTTPServer or xbSOAPEnvelope instance to provide secure communications. For more information about SSL/TLS, see the following document: SSL/TLS Frequently Asked Questions.
Initialization of an xbSSLContext object involves the following tasks:
Example:
// define SSL context
oSSL := xbSSLContext():new( SSL_v23_server )
// load certificate and check for errors
if oSSL:UseCertificateChainFile("MYCERT.PEM");
.and. oSSL:UsePrivateKeyFile("MYCERT.PEM");
.and. oSSL:CheckPrivateKey()
// attach SSL context to HTTP server instance
oHTTPS := xbHTTPServer():new(INADDR_ANY, 443, oSSL)
oHTTPS:start()
else
MsgBox("HTTPS server not started!" + chr(10) +;
"There is a problem with certificate." + chr(10) +;
xbSSLGetErrorString())
endif
:New([nConnectMethod]) -> self Creates a new instance of the xbSSLContext class that provides the framework to establish SSL/TLS enabled connections. The optional parameter, nConnectMethod is used to define the protocol to use when establishing a secure connection with a peer. Connection methods are provided for generic (client and server) use, server only, and client only use. The following constants, defined in Xb2NET.CH, can be used to specify the nConnectMethod type to use (the default is SSL_v3):
Instantiating the xbSSLContext class will allocate system resources that must later be released by calling the :Destroy() method once the object is no longer required. A runtime error will be raised if the security provider cannot be successfully initialized.
:Version
readonly/array
An array of OpenSSL library version information with following elements:
SSLEAY_VERSION - The OpenSSL library version number and release date, eg: "OpenSSL 0.9.7d 17 Mar 2004"
SSLEAY_CFLAGS - The compiler flags set for the compilation process in the form [compiler: ...] if available or [compiler: information not available] otherwise.
SSLEAY_BUILT_ON - The date of the build process in the form [built on: ...] if available or [built on: date not available] otherwise.
SSLEAY_PLATFORM - The target of the library build in the form [platform: ...] if available or [platform: information not available] otherwise.
SSLEAY_DIR - The default OpenSSL directory in the form [OPENSSLDIR: "..."] if available or [OPENSSLDIR: N/A] otherwise.
Life Cycle :Destroy() -> self Release system resources that have been allocated by this xbSSLContext instance. SSL/TLS Options :SetCipherList([cCipherList]) -> lSuccess A cipher suite is a set of algorithms that SSL/TLS uses to secure a connection. A variety of algorithms and cipher suites are provided by OpenSSL, however when designing secure applications, it is essential that algorithms having known security vulnerabilities not be allowed. This method is used to set the preference and order of ciphers that will be used when negotiating an SSL/TLS connection.
The list of ciphers is specified by a specially formatted string, cCipherList containing a colon-delimited list of algorithms or alias tags:
| OpenSSL Cipher Specification Tags | ||
|---|---|---|
| Tag | Description | |
| Key Exchange Algorithm: | ||
| kRSA | RSA key exchange | |
| kDHr | Diffie-Hellman key exchange with RSA key | |
| kDHd | Diffie-Hellman key exchange with DSA key | |
| kEDH | Ephemeral (temp.key) Diffie-Hellman key exchange (no cert) | |
| Authentication Algorithm: | ||
| aNULL | No authentication | |
| aRSA | RSA authentication | |
| aDSS | DSS authentication | |
| aDH | Diffie-Hellman authentication | |
| Cipher Encoding Algorithm: | ||
| eNULL | No encoding | |
| DES | DES encoding (not including triple-DES) | |
| 3DES | Triple-DES encoding | |
| RC4 | RC4 encoding | |
| RC2 | RC2 encoding | |
| IDEA | IDEA encoding | |
| AES | AES encoding | |
| MAC Digest Algorithm: | ||
| MD5 | MD5 hash function | |
| SHA1 | SHA1 hash function | |
| SHA | SHA hash function | |
| Aliases: | ||
| ALL | all ciphers suites except the eNULL ciphers which must be explicitly enabled. | |
| SSLv2 | all SSL version 2.0 ciphers | |
| SSLv3 | all SSL version 3.0 ciphers | |
| TLSv1 | all TLS version 1.0 ciphers | |
| EXP | all export ciphers, including 40 and 56 bit algorithms | |
| LOW | all ciphers with 64 or 56 bit encryption, but excluding export cipher suites | |
| MEDIUM | all ciphers with 128 bit encryption | |
| HIGH | all ciphers with greater than 128 bit encryption | |
| RSA | all ciphers using RSA key exchange | |
| DH | all ciphers using Diffie-Hellman key exchange | |
| EDH | all ciphers using Ephemeral Diffie-Hellman key exchange | |
| ADH | all ciphers using Anonymous Diffie-Hellman key exchange | |
| DSS | all ciphers using DSS authentication | |
| eNULL | all ciphers using no encryption | |
| Special Keywords: | ||
| @STRENGTH | sort the list of ciphers by their strength (key size) in order of highest to lowest. It should be specified last on the list. | |
| Prefix | Description |
|---|---|
| add cipher to list | |
| + | add ciphers to list and pull them to current location in list |
| - | remove cipher from list (can be added later again) |
| ! | remove cipher from list completely (can not be added later again) |
The OPENSSL.EXE command line utility can be used as a test tool to determine the appropriate cipherlist. It will convert OpenSSL cipher lists into ordered SSL cipher preference lists. To do this, type the following in a command prompt window:
openssl ciphers -v [cipherlist]
where [cipherlist] is the cipher list specification, eg:
openssl ciphers -v "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH"
:SetOptions(nOptions) -> nNewOptions
This method is used to provide fine-grained control over the SSL/TLS connections spawned from this context. It affects
the (external) protocol behavior of the SSL library. Changes to a SSL context do not affect already created SSL
connections.
The parameter nOptions is a set of SSL_OP_* flags that can be combined by summing individual flags together. Once an option is set, it cannot be cleared. This method only adds the options presented to the set of options already contained in this context. The method returns the new set of options. The following bug workaround options are available:
Certificate Management :SetDefaultPassword(cPassword) -> self Set the password that will be used to access data in a private key file that is in PEM (base64 encoded) format. Other items in PEM formatting (certificates) can also be encrypted, it is however not usual, as certificate information is considered public. :UseCertificateFile(cFileName, [nType]) -> lSuccess Loads the first certificate stored in file cFileName into memory. The formatting type of the certificate file can be specified in the second parameter nType. Two types of file formats are supported; SSL_FILETYPE_PEM (the default) and SSL_FILETYPE_ASN1. Files of type SSL_FILETYPE_ASN1 (also known as DER, binary encoding) can only contain one certificate or private key. Files of type SSL_FILETYPE_PEM can contain more than one item.
The method returns TRUE if successful. The following are the most likely causes of errors:
If a chain of certificates is required rather than just one certificate, then use the :UseCertificateChainFile() method instead. :UseCertificateChainFile(cFile) -> lSuccess Read a file that contains the certificate in PEM (base64 encoded) format, possibly followed by a sequence of CA certificates that should be sent to the peer in the certificate message. The method returns TRUE if successful. The following are the most likely causes of errors:
The entire list of certificates is passed to the remote node during the SSL/TLS handshake. If only one certificate is needed rather than a chain of certificates, then it is better to use the :UseCertificateFile() method instead. :UsePKCS12File(cPfxFile, cPassPhrase, [lAddExtraChainCerts]) -> lSuccess The PKCS#12 (aka PFX key storage) standard specifies a format for secure transportation of user identity information. This can be any sort of information, including certificates, passwords, and even portable keys. Many applications, including commonly used web browsers use PKCS#12 formatted credentials. Parameters: cPfxFile A character string containing the name (including path) of the PKCS#12 formatted file. If exported from Microsoft Internet Explorer, this file will typically have a .PFX extension. cPassPhrase A character string containing the password phrase under which the file was protected. lAddExtraChainCerts This is an optional logical parameter that determines whether additional certificates contained within the PKCS#12 file are added to the certificate chain. The default is to discard any additional certificates, however by setting this parameter to TRUE, any additional certificates contained within the file will be added to the certificate chain. :UsePrivateKeyFile(cFileName) -> lSuccess Add the first private key found in file cFileName to the context object. The private key file must be in PEM (base64 encoded) format. If it is encrypted, then the password must be specified by calling :SetDefaultPassword() prior to calling this method
The method returns TRUE if successful. The following are the most likely causes of errors (check the error stack by calling xbSSLGetLastError() to find out the reason):
:CheckPrivateKey() -> lSuccess Verify that the private key agrees with the corresponding public key in the loaded certificate. Both the certificate and private key must have already been loaded prior to calling this method. The method returns TRUE if successful. The following are the most likely causes of errors (check the error stack by calling xbSSLGetLastError() to find out the reason):
Peer Authentication :LoadVerifyLocations([cCAFileName], [cCAPathName]) -> lSuccess Verifying a certificate's authenticity requires that the verifying agent have a list of Certification Authorities (CAs) that it trusts. This method is used to provide the application with such a list in order for it to verify the peer. Parameters: cCAFileName The name of the file containing CA certificates in PEM (base64 encoded) format. More than one CA certificate may be present in the file. cCAPathName The name of a directory containing CA certificates in PEM (base64 encoded) format. Each file in the directory must contain only a single CA certificate and the files must be named by the subject name's hash and an extension of ".0". If more than one CA certificate with the same name hash value exist, the extension must be different (e.g. 9d66eef0.0, 9d66eef0.1 etc).
The method must be called with either the first or second parameter as NIL, but not both. An important difference between file and directory storage is the time when the certificates get loaded. With a flat file, the file is parsed and certificates loaded during the call to this method. However, with a directory, certificates are read only when needed, that is during the verification phase that occurs during the SSL/TLS handshake.
The method returns TRUE if successful. It may fail if both parameters are NIL or processing at one of the locations specified failed. Check the error stack by calling xbSSLGetLastError() to find out the reason. :SetVerify(nVerifyType) -> self This method is used to control how certificates and requests are handled during a SSL/TLS handshake. The parameter nVerifyType is used to specify the type of verification to perform on the peer's certificate. The following flags are provided for this purpose:
:SetVerifyDepth(nDepth) -> self This method is used to set the maximum allowable depth for peer authentication. In other words, it limits the number of certificates that will be verified in order to ensure the chain is trusted. For example, if the depth was set to 4 and 6 certificates are present in the chain to reach the trusted certificate, the verification would fail because the required depth would be too great. Setting the depth to zero allows chains of unlimited length to be used. The default depth limit is 9, allowing for the peer certificate and additional 9 CA certificates. :GetVerifyDepth() -> nDepth Returns the verification depth limit currently set in this SSL context as an integer numeric value. If no limit has been explicitly set, -1 is returned and the default value will be used.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:ConnectMethod
readonly/numeric
Reference to SSL_v* or TLS_v* connect method used at object initialization.
:Handle
readonly/numeric
Numeric context descriptor as used by OpenSSL.
This class simplifies session management by providing the ability of saving persistent data across multiple HTTP requests. The data managed by a session is stored in memory and will therefore only persist as long as the application is active.
:New() -> self Creates a new instance of the xbSession class. :ActiveSessions() -> nActiveSessionCount Return a count of the number of currently active sessions. :GetOpenSessions() -> aSessionList Returns a list of currently active sessions. The value returned is a one-dimensional array where each element contains a reference to an xbSession object. :KeepAlive(cHandle) -> lSuccess Find the session with the given session handle cHandle and reset its idle time to zero in order to make it look active. The method returns .T. if the session was found and updated, otherwise it returns .F. :Open(cHandle) -> oSession Find the session with the given cHandle session handle and return a reference to it. If a session with this handle does not exist, then a new session is created. :RestoreSessions([cFileName]) -> lSuccess Restore session data that was previously saved using :SaveSessions. If not specified, cFileName defaults to "xb2session.bin". The method returns .T. if session data was successfully restored. :SaveSessions([cFileName]) -> lSuccess Create a snapshot of all session data and save it to a file. If not specified, cFileName defaults to "xb2session.bin". Session data may later be restored by using the class method :RestoreSessions. The method returns .T. if session data was successfully saved. :SweepSessions(nMaxIdleTime, [bOnDelete]) -> self Remove sessions (including data stored by those sessions) that have been idle for more than nMaxIdleTime minutes. An optional codeblock bOnDelete can be provided which will be executed once for each session that is deleted from memory. When executed, one parameter is passed to the codeblock; a reference to the array containing the terminated session's data.
:LastSweep
exported/numeric
The time in seconds after midnight when the last :SweepSessions was performed.
:Close([bOnDelete]) -> self
Remove this session from the session manager and release all data maintained by it. An optional codeblock
bOnDelete can be provided which will be executed just before the session data is deleted from memory. When
executed, one parameter is passed to the codeblock; a reference to the array containing this session's data.
:GetCargo([cName]) -> xValue | aVarList | NIL, or
:GetVar([cName]) -> xValue | aVarList | NIL
Retrieve a named state variable previously saved with :SetCargo. If a parameter is not supplied or if
cName is NIL, then the method will return an array of all name/value pairs saved in the current session object.
:SetCargo([xName], [xValue]) -> xPreviousValue | aPreviousVarList, or
:SetVar([xName], [xValue]) -> xPreviousValue | aPreviousVarList
Store the value xValue using a symbolic character name xName until the session is closed. This
method is quite flexible and can be used is several ways:
When xName and xValue are both NIL then delete all state variables (session is not closed)
When xValue is NIL, state variable with the name xName is deleted
When xName is an array, replace all name/value pairs with passed array
Otherwise add/replace value
:MinutesIdle() -> nMinutesIdle
Returns the number of minutes that this session has been idle.
:UpTime() -> {nDays, nHrs, nMin, nSec}
Returns a one dimensional array specifying amount of time the session has been open. The following array
constants available in Xb2NET.CH provide access to the individual array elements:
UPTIME_DAY - number of days
UPTIME_HRS - number of hours
UPTIME_MIN - number of minutes
UPTIME_SEC - number of seconds
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:Handle
exported/character
a unique character string representing the session ID.
:DateStarted
readonly/date
Date session was created.
:TimeStarted
readonly/numeric
Time session was created (seconds after midnight).
Provides generic methods for reading and writing to data stream files.
:New(xFile) -> self Create a new instance of the xbStream class. The parameter xFile provides a reference to the target data stream file. It may be specified as a character string containing the name of the target file with drive and path information, or as an integer numeric value providing the operating system file handle of an open data stream file.
Note: If a file handle is provided instead of a file name, then :Read() and :Write() will commence at current file pointer offset. In addition, when the object is initialized with a file handle, the :Close() method may not be used to close the file, it must be closed by the calling routine.
:AsString() -> cString Return contents of entire data stream as a character string.
Warning: If the data stream is very large, it is possible that this method will consume more memory than is available on the host system. Use, :Read() instead to process the stream in smaller chunks. :Close() -> lSuccess Close the underlying data file containing data stream. The method returns .T. (true) when the underlying data file was closed successfully, otherwise it returns .F. (false).
Note: The underlying file will only be closed if it was originally opened via the :Open() or :Create() methods. If the data file was opened externally such that the xbStream object was initialized by providing a file handle, then it may not be closed via this method. :Create([nAttribute]) -> nHandle | -1 Create a data stream file referenced in the :Name property and open it for write access. If the xbStream object was initialized by providing a file handle, so that the target file name is unknown, then a new file will not be created. The optional nAttribute parameter is an integer numeric value which sets the access mode for the file. If supplied, nAttribute must be set to one of the following constants defined in FILEIO.CH:
FC_NORMAL - Creates file with read and write access (the default).
FC_READONLY - Creates file with read access.
FC_HIDDEN - Creates hidden file.
FC_SYSTEM - Creates system file.
The method returns an integer numeric value representing the file handle provided by the operating system. If the file could not be created, then the method returns -1. The nature of the error can be determined by calling the standard Xbase++ function FError(). :GetName() -> cFileName | NIL Returns disk file name (excluding drive and path information) containing data stream. The method will return NIL if the file name is unknown. The complete file name with drive and path information is stored in the :Name ivar. :GetSize() -> nSize Returns total size in bytes of data stream file. :Open([nMode]) -> nHandle | -1 Open the data stream file referenced by the :Name property. The target file may also be opened externally and manipulated using xbStream methods by supplying a file handle to the init method. If opened externally, the file must also be closed externally.
The optional nMode parameter is an integer numeric value that provides the mode for data access. If not supplied, the file is opened in "read-only" and "shared" mode. Symbolic constants providing possible values for nMode are defined in FILEIO.CH with prefix FO_*. For additional information, please consult the Xbase++ documentation for function FOpen().
The method returns an integer numeric value representing the file handle provided by the operating system. If the file could not be opened, then the method returns -1. The nature of the error can be determined by calling the standard Xbase++ function FError(). :Read(@cBuffer, [nBytes]) -> nBytesRead Read nBytes from data stream into cBuffer, a pre-sized character string that is passed by reference. The parameter nBytes is an optional integer numeric value that determines the number of bytes to read. If it is supplied it must be smaller than or equal to the size of cBuffer. If not provided, nBytes defaults to the size of cBuffer.
The method returns the actual number of bytes that were read from the data stream. The return value should be the same as nBytes. If it is less than nBytes then either an error occurred or the end of the data stream has been reached. The nature of the error can be determined by calling the standard Xbase++ function FError(). :Write(cBuffer, [nBytes]) -> nBytesWritten Write a character string from cBuffer into the data stream. nBytes is an optional integer numeric value that determines the number of characters written into the data stream from cBuffer. If nBytes is not provided, the entire contents of cBuffer are written to the data stream.
The method returns an integer numeric value indicating the number of bytes actually written into the data stream. A return value that is less than nBytes indicates that an error occurred during the write operation. The nature of the error can be determined by calling the standard Xbase++ function FError().
:BytesRead
readonly/numeric
A cumulative total of number of bytes read from the data stream.
:BytesWritten
readonly/numeric
A cumulative total of number of bytes written to the data stream.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:Handle
exported/numeric
An integer numeric value representing the file handle provided by the operating system for the open data stream.
:MimeType
exported/character
The MIME encoding type of the data stream.
:Name
exported/character
The data stream disk file name including drive and path. If the xbStream object was initialized by providing a target file handle,
then the name of the underlying file will be unknown.
:Options
exported/character
A character string providing optional information about the data stream. For example, if the data stream was transmitted as a MIME
payload, then this property may include information such as content description, encoding information and content disposition.
Class for logging client requests using Extended Log File Format (W3C Working Draft WD-logfile-960323). This log format is compatible with Microsoft Internet Information Server (IIS) and is supported by many third party web log analyzers.
:New([cSoftware], [nTimePeriod], [nFields], [cFilePrefix]) -> self Create a new instance of the xbTLog class. All parameters are optional. Parameters: cSoftware On optional character string that is used to identify the software which generated the log. If not provided, the value of xbHTTPServer():ServerName will be used instead. nTimePeriod Optional numeric value specifying the time period when a new log file is created. The following options are possible:
TLOG_HOURLY - Log files are created hourly
TLOG_DAILY - Log files are created daily starting with the first entry that occurs after midnight.
TLOG_WEEKLY - Log files are created weekly starting with the first entry that occurs after midnight Saturday.
TLOG_MONTHLY - Log files are created monthly starting with the first entry that occurs after midnight of the last day of the month.
TLOG_UNLIMITED - Data is always appended to the same log file.
If not specified the default is TLOG_DAILY. For more information see :TimePeriod in the object properties section below. nFields Optional set of bitmap flags specifying the information to be recorded in each log entry. The flags are defined in Xb2NET.CH with the prefix EXLOG_* and can be added together to define the set of fields to be recorded. For more information see :Fields in the object properties section below.
If not specified, nFields defaults to:
EXLOG_TIME + EXLOG_C_IP + EXLOG_CS_METHOD + EXLOG_CS_URI_STEM + EXLOG_CS_URI_QUERY + EXLOG_SC_STATUS +
EXLOG_SC_BYTES + EXLOG_CS_BYTES + EXLOG_TIME_TAKEN + EXLOG_CS_VERSION + EXLOG_CS_REFERRER
cFilePrefix
Optional character string providing the log file name prefix. If not specified the file name prefix defaults to "trans".
Example:
oTLog := xbTLog():new()
oTLog:SetDir(".\LogFiles")
oTLog:TimePeriod := TLOG_MONTHLY
oTLog:Fields := EXLOG_DATE + EXLOG_TIME + EXLOG_C_IP + EXLOG_CS_METHOD + EXLOG_CS_URI_STEM + EXLOG_CS_URI_QUERY + EXLOG_SC_STATUS
oServer := xbHTTPServer():new()
oServer:TLog := oTLog
oServer:RootDir := ".\www_root"
oServer:IndexFile := "index.htm"
oServer:onGET := {|o| HTTPHandler(o)}
oServer:onPOST := {|o| HTTPHandler(o)}
oServer:start()
:Close() -> self Close current log file. Note that calling this method does not terminate logging, the log file will be reopened by the :Write() method. To pause logging, use the :Stop() method. :SetDir(cPath) -> cPath Set the directory path where the log files will be written. If the specified directory path does not exist, it will be created. :Start() -> self Restart logging after it has been disabled with the :Stop() method. :Stop() -> self Disable logging and close current log file. Logging can be restarted by using the :Start() method. :Write(cString) -> nErrorCode Write a pre-formatted log entry into the log file. cString is a character string containing the log entry record to be written. It must be properly formatted as per W3C Working Draft WD-logfile-960323 and correspond to the :Fields property.
The method returns zero if successful. Otherwise, an integer numeric OS error code is returned.
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:Fields
exported/numeric
Set of bitmap flags specifying the information to be recorded in each log entry. The following bitmap constants defined in
Xb2NET.CH provide the available list of fields. These can be added together to define the set of fields to be
recorded in each log entry:
EXLOG_DATE - Date of activity.
EXLOG_TIME - Time of activity.
EXLOG_C_IP - IP address of client who accessed the server.
EXLOG_CS_USERNAME - Name of authenticated user who accessed the server.
EXLOG_S_SITENAME - HTTP server appname.
EXLOG_S_COMPUTERNAME - Name of server on which the log entry was generated.
EXLOG_S_IP - IP address of server on which the log entry was generated.
EXLOG_S_PORT - Server port number the client connected to.
EXLOG_CS_METHOD - The action client was trying to perform (eg. GET, POST, etc...).
EXLOG_CS_URI_STEM - The resource accessed (eg. index.htm).
EXLOG_CS_URI_QUERY - The query, if any, the client was trying to perform.
EXLOG_SC_STATUS - The response status of the action.
EXLOG_SC_WIN32_STATUS - The response status of the action as a win32 error code.
EXLOG_SC_BYTES - Number of bytes sent by the server.
EXLOG_CS_BYTES - Number of bytes received by the server.
EXLOG_TIME_TAKEN - Duration of time, in milliseconds, that the action consumed.
EXLOG_CS_VERSION - The protocol version that the client used (eg. HTTP/1.1).
EXLOG_CS_HOST - The HTTP 'host' header field.
EXLOG_CS_USER_AGENT - The HTTP browser used by the client.
EXLOG_CS_COOKIE - The content of a HTTP cookie received, if any.
EXLOG_CS_REFERRER - The previous HTTP site visited by the user, if it provided a link to the current site.
The default is:
EXLOG_TIME + EXLOG_C_IP + EXLOG_CS_METHOD + EXLOG_CS_URI_STEM + EXLOG_CS_URI_QUERY + EXLOG_SC_STATUS +
EXLOG_SC_BYTES + EXLOG_CS_BYTES + EXLOG_TIME_TAKEN + EXLOG_CS_VERSION + EXLOG_CS_REFERRER.
:FilePrefix
exported/character
The log file name prefix.
:isActive
readonly/logical
A logical flag indicating if logging is enabled. The status of this flag is controlled by the :Start() and
:Stop() methods.
:LogDir
readonly/character
The directory path where log files are written.
:Software
exported/character
A character string that is used to identify the software which generated the log.
:TimePeriod
exported/numeric
Specifies the time period when a new log file is created. The following options, defined in Xb2NET.CH, are possible:
A Uniform Resource Identifier (URI) is a compact string of characters for identifying an abstract or physical
resource. This class provides methods for parsing a URI into its individual components as well as methods for
combining these individual components into an encoded string safe for transport. A URI consists of the following
components (some of which may not be present is all URI's):
[scheme]://[authority][path]?[query]#[fragment]
:New([cURIString]) -> self Creates a new instance of the xbURI class and optionally parses a URI string cURIString into it's individual components. If passed, the cURIString must be in URL encoded format in order to parse correctly.
:AsString([lResourceOnly]) -> cEncodedURIString Combine the URI components and encode the result suitable for HTTP transport.
An optional logical parameter lResourceOnly, can be set to .T. in order to return only the "resource"
portion of the URI. A URI resource consists of the path, query and fragment portions only, eg:
/physics/letters/quantum.htm?uid=maxwell#qed
If the parameter lResourceOnly is NIL or .F., then the full URI will be returned. :GetVar([cName]) -> xValue | aVarList | NIL Retrieve a URI query parameter. If cName is NIL, then the method will return an array listing all query parameters as name/value pairs. :Parse(cURIString) -> self Parse the URI string cURIString into it's individual components. The specified URI string must be in URL encoded format in order to parse correctly. :Reset() -> self Reinitialize object. :SetVar([xName], [cValue]) -> xPreviousValue | aPreviousVarList Assign the value cValue to the query parameter xName. This method and can be used is several ways:
When xName and cValue are both NIL then delete all query parameters
When cValue is NIL, then remove the query parameter xName
When xName is an array, replace all query parameters with the passed array of name/value pairs
Otherwise add or replace a query parameter value
:Cargo
exported/any data type
Used to attach additional information to the object as required by the programmer.
:isAbsolute
exported/logical
Indicates if URI path is absolute (.T.) or relative (.F.). Absolute URI paths include a scheme component.
:isQuery
exported/logical
Indicates if URI contains a query component. This property can be set to .T. to append a query marker (the question
mark '?' character) to the final URI even though no query component exists. The presence of the query marker can
be significant on some HTTP servers.
:Scheme
exported access-assign method/character
This is the name of the scheme being used. Some examples are:
http, ftp, gopher, mailto, news, telnet
:Authority
exported access-assign method/character
The authority component is the top hierarchical element in the URI that is typically defined by a server, eg:
www.sqlexpress.net, atlas.gc.ca, cgi.ebay.ca
:Path
exported access-assign method/character
The path component identifies the target resource within the scope of the Authority (or Scheme if there is no Authority), eg:
/, /english/facts/index.html, /aw-cgi/eBayISAPI.dll
:Query
exported access-assign method/character
The query component is a string of information to be interpreted by the target resource. It is separated from
the target resource by a question mark (?) character. The :GetVar and :SetVar methods can be
used to get and set individual parameters within the query. The following is an example of a query
component:
UID=1836743&ITEM=XE342&QTY=3
:Fragment
exported access-assign method/character
A URI fragment is used to provide additional retrieval information to the client after the target resource
has been successfully loaded. Technically, a fragment is not really a part of the URI, but is is often used in
conjunction with a URI. It is separated from the URI by a crosshatch (#) character, eg:
http://www.sqlexpress.net/download.htm#sqlexpress
