cpython/Doc/lib/libsimplexmlrpc.tex
2006-01-11 00:18:43 +00:00

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\section{\module{SimpleXMLRPCServer} ---
Basic XML-RPC server}
\declaremodule{standard}{SimpleXMLRPCServer}
\modulesynopsis{Basic XML-RPC server implementation.}
\moduleauthor{Brian Quinlan}{brianq@activestate.com}
\sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
\versionadded{2.2}
The \module{SimpleXMLRPCServer} module provides a basic server
framework for XML-RPC servers written in Python. Servers can either
be free standing, using \class{SimpleXMLRPCServer}, or embedded in a
CGI environment, using \class{CGIXMLRPCRequestHandler}.
\begin{classdesc}{SimpleXMLRPCServer}{addr\optional{,
requestHandler\optional{,
logRequests\optional{allow_none\optional{, encoding}}}}}
Create a new server instance. This class
provides methods for registration of functions that can be called by
the XML-RPC protocol. The \var{requestHandler} parameter
should be a factory for request handler instances; it defaults to
\class{SimpleXMLRPCRequestHandler}. The \var{addr} and
\var{requestHandler} parameters are passed to the
\class{\refmodule{SocketServer}.TCPServer} constructor. If
\var{logRequests} is true (the default), requests will be logged;
setting this parameter to false will turn off logging.
The \var{allow_none} and \var{encoding} parameters are passed on to
\module{xmlrpclib} and control the XML-RPC responses that will be returned
from the server.
\versionchanged[The \var{allow_none} and \var{encoding} parameters were added]{2.5}
\end{classdesc}
\begin{classdesc}{CGIXMLRPCRequestHandler}{\optional{allow_none\optional{, encoding}}}
Create a new instance to handle XML-RPC requests in a CGI
environment.
The \var{allow_none} and \var{encoding} parameters are passed on to
\module{xmlrpclib} and control the XML-RPC responses that will be returned
from the server.
\versionadded{2.3}
\versionchanged[The \var{allow_none} and \var{encoding} parameters were added]{2.5}
\end{classdesc}
\begin{classdesc}{SimpleXMLRPCRequestHandler}{}
Create a new request handler instance. This request handler
supports \code{POST} requests and modifies logging so that the
\var{logRequests} parameter to the \class{SimpleXMLRPCServer}
constructor parameter is honored.
\end{classdesc}
\subsection{SimpleXMLRPCServer Objects \label{simple-xmlrpc-servers}}
The \class{SimpleXMLRPCServer} class is based on
\class{SocketServer.TCPServer} and provides a means of creating
simple, stand alone XML-RPC servers.
\begin{methoddesc}[SimpleXMLRPCServer]{register_function}{function\optional{,
name}}
Register a function that can respond to XML-RPC requests. If
\var{name} is given, it will be the method name associated with
\var{function}, otherwise \code{\var{function}.__name__} will be
used. \var{name} can be either a normal or Unicode string, and may
contain characters not legal in Python identifiers, including the
period character.
\end{methoddesc}
\begin{methoddesc}[SimpleXMLRPCServer]{register_instance}{instance\optional{,
allow_dotted_names}}
Register an object which is used to expose method names which have
not been registered using \method{register_function()}. If
\var{instance} contains a \method{_dispatch()} method, it is called
with the requested method name and the parameters from the request. Its
API is \code{def \method{_dispatch}(self, method, params)} (note that
\var{params} does not represent a variable argument list). If it calls an
underlying function to perform its task, that function is called as
\code{func(*params)}, expanding the parameter list.
The return value from \method{_dispatch()} is returned to the client as
the result. If
\var{instance} does not have a \method{_dispatch()} method, it is
searched for an attribute matching the name of the requested method.
If the optional \var{allow_dotted_names} argument is true and the
instance does not have a \method{_dispatch()} method, then
if the requested method name contains periods, each component of the
method name is searched for individually, with the effect that a
simple hierarchical search is performed. The value found from this
search is then called with the parameters from the request, and the
return value is passed back to the client.
\begin{notice}[warning]
Enabling the \var{allow_dotted_names} option allows intruders to access
your module's global variables and may allow intruders to execute
arbitrary code on your machine. Only use this option on a secure,
closed network.
\end{notice}
\versionchanged[\var{allow_dotted_names} was added to plug a security hole;
prior versions are insecure]{2.3.5, 2.4.1}
\end{methoddesc}
\begin{methoddesc}{register_introspection_functions}{}
Registers the XML-RPC introspection functions \code{system.listMethods},
\code{system.methodHelp} and \code{system.methodSignature}.
\versionadded{2.3}
\end{methoddesc}
\begin{methoddesc}{register_multicall_functions}{}
Registers the XML-RPC multicall function system.multicall.
\end{methoddesc}
Example:
\begin{verbatim}
from SimpleXMLRPCServer import SimpleXMLRPCServer
# Create server
server = SimpleXMLRPCServer(("localhost", 8000))
server.register_introspection_functions()
# Register pow() function; this will use the value of
# pow.__name__ as the name, which is just 'pow'.
server.register_function(pow)
# Register a function under a different name
def adder_function(x,y):
return x + y
server.register_function(adder_function, 'add')
# Register an instance; all the methods of the instance are
# published as XML-RPC methods (in this case, just 'div').
class MyFuncs:
def div(self, x, y):
return x // y
server.register_instance(MyFuncs())
# Run the server's main loop
server.serve_forever()
\end{verbatim}
The following client code will call the methods made available by
the preceding server:
\begin{verbatim}
import xmlrpclib
s = xmlrpclib.Server('http://localhost:8000')
print s.pow(2,3) # Returns 2**3 = 8
print s.add(2,3) # Returns 5
print s.div(5,2) # Returns 5//2 = 2
# Print list of available methods
print s.system.listMethods()
\end{verbatim}
\subsection{CGIXMLRPCRequestHandler}
The \class{CGIXMLRPCRequestHandler} class can be used to
handle XML-RPC requests sent to Python CGI scripts.
\begin{methoddesc}{register_function}{function\optional{, name}}
Register a function that can respond to XML-RPC requests. If
\var{name} is given, it will be the method name associated with
function, otherwise \var{function.__name__} will be used. \var{name}
can be either a normal or Unicode string, and may contain
characters not legal in Python identifiers, including the period
character.
\end{methoddesc}
\begin{methoddesc}{register_instance}{instance}
Register an object which is used to expose method names
which have not been registered using \method{register_function()}. If
instance contains a \method{_dispatch()} method, it is called with the
requested method name and the parameters from the
request; the return value is returned to the client as the result.
If instance does not have a \method{_dispatch()} method, it is searched
for an attribute matching the name of the requested method; if
the requested method name contains periods, each
component of the method name is searched for individually,
with the effect that a simple hierarchical search is performed.
The value found from this search is then called with the
parameters from the request, and the return value is passed
back to the client.
\end{methoddesc}
\begin{methoddesc}{register_introspection_functions}{}
Register the XML-RPC introspection functions
\code{system.listMethods}, \code{system.methodHelp} and
\code{system.methodSignature}.
\end{methoddesc}
\begin{methoddesc}{register_multicall_functions}{}
Register the XML-RPC multicall function \code{system.multicall}.
\end{methoddesc}
\begin{methoddesc}{handle_request}{\optional{request_text = None}}
Handle a XML-RPC request. If \var{request_text} is given, it
should be the POST data provided by the HTTP server,
otherwise the contents of stdin will be used.
\end{methoddesc}
Example:
\begin{verbatim}
class MyFuncs:
def div(self, x, y) : return x // y
handler = CGIXMLRPCRequestHandler()
handler.register_function(pow)
handler.register_function(lambda x,y: x+y, 'add')
handler.register_introspection_functions()
handler.register_instance(MyFuncs())
handler.handle_request()
\end{verbatim}