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author | Eric S. Raymond <esr@thyrsus.com> | 2001-07-12 02:39:45 (GMT) |
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committer | Eric S. Raymond <esr@thyrsus.com> | 2001-07-12 02:39:45 (GMT) |
commit | e304bb9eec7a2124c301d1c54635dea4dad2c1aa (patch) | |
tree | bc2a9fab9f1f50fadd67ea80287d56fc22951a93 /Doc/lib/libxmlrpclib.tex | |
parent | 682d5f3cdace81b656d0d76e298f657e2da75b03 (diff) | |
download | cpython-e304bb9eec7a2124c301d1c54635dea4dad2c1aa.zip cpython-e304bb9eec7a2124c301d1c54635dea4dad2c1aa.tar.gz cpython-e304bb9eec7a2124c301d1c54635dea4dad2c1aa.tar.bz2 |
First version of xmlrpclib docs. Probably has markup errors; is not complete,
could probably stand to have some of the internal things like Marshaller
documented. But I think it does a decent job on the entry points and
externally visible things.
Fred and Fredrik, do your stuff! You both need to proof this.
Diffstat (limited to 'Doc/lib/libxmlrpclib.tex')
-rw-r--r-- | Doc/lib/libxmlrpclib.tex | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/Doc/lib/libxmlrpclib.tex b/Doc/lib/libxmlrpclib.tex new file mode 100644 index 0000000..0afa2aa --- /dev/null +++ b/Doc/lib/libxmlrpclib.tex @@ -0,0 +1,237 @@ +\section{\module{xmlrpclib} --- XML-RPC client access} + +\declaremodule{standard}{xmlrpclib} +\modulesynopsis{XML-RPC client access.} +\moduleauthor{Fredrik Lundh}{effbot@telia.com} +\sectionauthor{Eric S. Raymond}{esr@snark.thyrsus.com} + +% Not everyting is documented yet. It might be good to describe +% Marshaller, Unmarshaller, getparser, dumps, loads, and Transport. + +\versionadded{2.2} + +XML-RPC is a Remote Procedure Call method that uses XML passed via +HTTP as a transport. With it, a client can call methods with +parameters on a remote server (the server is named by a URI) and get back +structured data. This module supports writing XML-RPC client code; it +handles all the details of translating between conformable Python +objects and XML on the wire. + +\begin{seealso} + \seetitle{http://xmlrpc-c.sourceforge.net/xmlrpc-howto/xmlrpc-howto.html} + {XML-RPC HOWTO}{A good description of XML operation and client + software in several languages. Contains pretty much + everything an XML-RPC client developer needs to know.} + \seetitle{http://xmlrpc-c.sourceforge.net/hacks.php} + {XML-RPC-Hacks page}{Extensions for various open-source + libraries to support instrospection and multicall.} +\end{seealso} + +\begin{classdesc}{Server}{\optional{uri\optional{, transport, encoding, verbose}}} +A \class{Server} instance is a server proxy that manages communication +with a remote XML-RPC server. The required first argument is a URI +(Uniform Resource Indicator), and will normally be the URL of the +server. The optional second argument is a transport factory instance; +by default it is an internal \class{SafeTransport} instance for https: +URLs and an internal HTTP \class{Transport} instance otherwise. The +optional third argument is an encoding, by default UTF-8. The optional +fourth argument is a debugging flag. + +The returned instance is a proxy object with methods that can be used +to invoke corresponding RPC calls on the remote server. If the remote +server supports the introspection API, the proxy can also be used to query +the remote server for the methods it supports (service discovery) and +fetch other server-associated metadata. + +\class{Server} instance methods take Python basic types and objects as +arguments and return Python basic types and classes. Types that are +conformable (e.g. that can be marshalled through XML), include the +following (and except where noted, they are unmarshalled as the same +Python type): + +\begin{tableii}{l|l}{constant}{Name}{Meaning} + \lineii{boolean}{The True and False constants that then module supplies} + \lineii{integers}{Pass in directly} + \lineii{floating-point numbers}{Pass in directly} + \lineii{strings}{Pass in directly} + \lineii{arrays}{Any Python sequence type containing conformable + elements. Arrays are returned as lists} + \lineii{structures}{A Python dictionary. Keys must be strings, + values may be any conformable type.} + \lineii{dates}{in seconds since the epoch; pass in an instance of the + \class{DateTime} wrapper class} + \lineii{binary data}{pass in an instance of the \class{Binary} wrapper class} +\end{tableii} + +This is the full set of data types supported by XML-RPC. Method calls +may also return a special \class{Fault} instance, used to signal XML-RPCserver +errors, or a \class{ProtocolError} instance used to signal an error in +the HTTP/HTTPS transport layer. + +\end{classdesc} + +\subsection{Server Objects \label{server-objects}} + +A \class{Server} instance proxy object has a method corresponding to +each remote procedure call accepted by the XML-RPC server. Calling +the method performs an RPC, dispatched by both name and argument +signature (e.g. the same method name can be overloaded with multiple +argument signatures). The RPC finishes by returning a value, which +may be either returned data in a conformant type or a \class{Fault} or +\class{ProtocolError} object indicating an error. + +Servers that support the XML introspection API support some common +methods grouped under the reserved \member{system} member: + +\begin{methoddesc}{system.listMethods}{} +This method returns a list of strings, one for each (non-system) +method supported by the XML-RPC server. +\end{methoddesc} + +\begin{methoddesc}{system.methodHelp}{name} +This method takes one parameter, the name of a method implemented by +the XML-RPC server.It returns an array of possible signatures for this +method. A signature is an array of types. The first of these types is +the return type of the method, the rest are parameters. + +Because multiple signatures (ie. overloading) is permitted, this method +returns a list of signatures rather than a singleton. + +Signatures themselves are restricted to the top level parameters +expected by a method. For instance if a method expects one array of +structs as a parameter, and it returns a string, its signature is +simply "string, array". If it expects three integers and returns a +string, its signature is "string, int, int, int". + +If no signature is defined for the method, a non-array value is +returned. In Python this means that the type of the returned +value will be something other that list. +\end{methoddesc} + +\begin{methoddesc}{system.methodHelp}{name} +This method takes one parameter, the name of a method implemented by +the XML-RPC server. It returns a documentation string describing the +use of that method. If no such string is available, an empty string is +returned. The documentation string may contain HTML markup. +\end{methoddesc} + +Introspection methods are currently supported by servers written in +PHP, C and Microsoft .NET. Partial introspection support is included +in recent updates to UserLand Frontier. Introspection support for +Perl, Python and Java is available at the XML-RPC Hacks page. + +\subsection{Boolean Objects \label{boolean-objects}} + +This class may be initialized from any Python value; the instance +returned depends onlyon its truth value. It supports various Python +operators through \class{__cmp__}, \class{__repr__}, \class{__int__}, +and \class{__nonzero__} methods, all implemented in the obvious ways. + +It also has the following method, supported mainly for internal use by +the unmarshalling code: + +\begin{methoddesc}{encode}{out} +Write the XML-RPC encoding of this Boolean item to the out stream object. +\end{methoddesc} + +\subsection{DateTime Objects \label{datetime-objects}} + +This class may initialized from date in seconds since the epoch, a +time tuple, or an ISO 8601 time/date string. It has the following +methods, supported mainly for internal use by the +marshalling/unmarshalling code: + +\begin{methoddesc}{decode}{string} +Accept a string as the instance's new time value. +\end{methoddesc} + +\begin{methoddesc}{encode}{out} +Write the XML-RPC encoding of this DateTime item to the out stream object. +\end{methoddesc} + +It also supports certain of Python's built-in operators through +\method{_cmp__} and \method{__repr__} methods. + +\subsection{Binary Objects \label{binary-objects}} + +This class may initialized from string data (which may include NULs). +It has the following methods, supported mainly for internal use by the +marshalling/unmarshalling code: + +\begin{methoddesc}{decode}{string} +Accept a base64 string and decode it as the instance's new data. +\end{methoddesc} + +\begin{methoddesc}{encode}{out} +Write the XML-RPC base 64 encoding of this binary item to the out stream object. +\end{methoddesc} + +It also supports certain of Python's built-in operators through a +\method{_cmp__} method. + +\subsection{Fault Objects \label{fault-objects}} + +A \class{Fault} object encapsulates the content of an XML-RPC fault tag. +Fault objects have the following members: + +\begin{memberdesc}{faultCode} +A string indicating the fault type. +\end{memberdesc} + +\begin{memberdesc}{faultString} +A string containing a diagnostic message associated with the fault. +\end{memberdesc} + +\subsection{ProtocolError Objects \label{protocol-error-objects}} + +A \class{ProtocolError} object describes a protocol error in the +underlying transport layer (such as a 404 `not found' error if the +server named by the URI does not exist). It has the following +members: + +\begin{memberdesc}{url} +The URI or URL that triggered te error. +\end{memberdesc} + +\begin{memberdesc}{errcode} +The error code. +\end{memberdesc} + +\begin{memberdesc}{errmsg} +The eror message of diagnostic string. +\end{memberdesc} + +\begin{memberdesc}{headers} +A string containing the headers of the HTTP/HTTPS request that +triggered the error. +\end{memberdesc} + +\subsection{Convenience Functions} + +\begin{funcdesc}{boolean}{value, \optional{truefals=(False, True)}} +Convert any Python value to one of the XML-RPC boolean constants. +The optional second argument supplies a conversion table to be indexed +by the first argument's Python truth value. +\end{funcdesc} + +\begin{funcdesc}{binary}{data} +Trivially convert any Python string to a \class{Binary} object. +\end{funcdesc} + +\subsection{Example of Client Usage + +\begin{verbatim} + # simple test program (from the XML-RPC specification) + + # server = Server("http://localhost:8000") # local server + server = Server("http://betty.userland.com") + + print server + + try: + print server.examples.getStateName(41) + except Error, v: + print "ERROR", v +\end{verbatim} + +% End |