20.24. "SimpleXMLRPCServer" — Basic XML-RPC server
**************************************************

注解: The "SimpleXMLRPCServer" module has been merged into
  "xmlrpc.server" in Python 3.  The *2to3* tool will automatically
  adapt imports when converting your sources to Python 3.

2.2 新版功能.

**Source code:** Lib/SimpleXMLRPCServer.py

======================================================================

The "SimpleXMLRPCServer" module provides a basic server framework for
XML-RPC servers written in Python.  Servers can either be free
standing, using "SimpleXMLRPCServer", or embedded in a CGI
environment, using "CGIXMLRPCRequestHandler".

class SimpleXMLRPCServer.SimpleXMLRPCServer(addr[, requestHandler[, logRequests[, allow_none[, encoding[, bind_and_activate]]]])

   Create a new server instance.  This class provides methods for
   registration of functions that can be called by the XML-RPC
   protocol.  The *requestHandler* parameter should be a factory for
   request handler instances; it defaults to
   "SimpleXMLRPCRequestHandler".  The *addr* and *requestHandler*
   parameters are passed to the "SocketServer.TCPServer" constructor.
   If *logRequests* is true (the default), requests will be logged;
   setting this parameter to false will turn off logging.   The
   *allow_none* and *encoding* parameters are passed on to
   "xmlrpclib" and control the XML-RPC responses that will be returned
   from the server. The *bind_and_activate* parameter controls whether
   "server_bind()" and "server_activate()" are called immediately by
   the constructor; it defaults to true. Setting it to false allows
   code to manipulate the *allow_reuse_address* class variable before
   the address is bound.

   在 2.5 版更改: The *allow_none* and *encoding* parameters were
   added.

   在 2.6 版更改: The *bind_and_activate* parameter was added.

class SimpleXMLRPCServer.CGIXMLRPCRequestHandler([allow_none[, encoding]])

   Create a new instance to handle XML-RPC requests in a CGI
   environment.  The *allow_none* and *encoding* parameters are passed
   on to  "xmlrpclib" and control the XML-RPC responses that will be
   returned  from the server.

   2.3 新版功能.

   在 2.5 版更改: The *allow_none* and *encoding* parameters were
   added.

class SimpleXMLRPCServer.SimpleXMLRPCRequestHandler

   Create a new request handler instance.  This request handler
   supports "POST" requests and modifies logging so that the
   *logRequests* parameter to the "SimpleXMLRPCServer" constructor
   parameter is honored.


20.24.1. SimpleXMLRPCServer Objects
===================================

The "SimpleXMLRPCServer" class is based on "SocketServer.TCPServer"
and provides a means of creating simple, stand alone XML-RPC servers.

SimpleXMLRPCServer.register_function(function[, name])

   Register a function that can respond to XML-RPC requests.  If
   *name* is given, it will be the method name associated with
   *function*, otherwise "function.__name__" will be used.  *name* can
   be either a normal or Unicode string, and may contain characters
   not legal in Python identifiers, including the period character.

SimpleXMLRPCServer.register_instance(instance[, allow_dotted_names])

   Register an object which is used to expose method names which have
   not been registered using "register_function()".  If *instance*
   contains a "_dispatch()" method, it is called with the requested
   method name and the parameters from the request.  Its API is "def
   _dispatch(self, method, params)" (note that *params* does not
   represent a variable argument list).  If it calls an underlying
   function to perform its task, that function is called as
   "func(*params)", expanding the parameter list. The return value
   from "_dispatch()" is returned to the client as the result.  If
   *instance* does not have a "_dispatch()" method, it is searched for
   an attribute matching the name of the requested method.

   If the optional *allow_dotted_names* argument is true and the
   instance does not have a "_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.

   警告: Enabling the *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.

   在 2.3.5, 版更改: 2.4.1 *allow_dotted_names* was added to plug a
   security hole; prior versions are insecure.

SimpleXMLRPCServer.register_introspection_functions()

   Registers the XML-RPC introspection functions "system.listMethods",
   "system.methodHelp" and "system.methodSignature".

   2.3 新版功能.

SimpleXMLRPCServer.register_multicall_functions()

   Registers the XML-RPC multicall function system.multicall.

SimpleXMLRPCRequestHandler.rpc_paths

   An attribute value that must be a tuple listing valid path portions
   of the URL for receiving XML-RPC requests.  Requests posted to
   other paths will result in a 404 “no such page” HTTP error.  If
   this tuple is empty, all paths will be considered valid. The
   default value is "('/', '/RPC2')".

   2.5 新版功能.

SimpleXMLRPCRequestHandler.encode_threshold

   If this attribute is not "None", responses larger than this value
   will be encoded using the *gzip* transfer encoding, if permitted by
   the client.  The default is "1400" which corresponds roughly to a
   single TCP packet.

   2.7 新版功能.


20.24.1.1. SimpleXMLRPCServer Example
-------------------------------------

Server code:

   from SimpleXMLRPCServer import SimpleXMLRPCServer
   from SimpleXMLRPCServer import SimpleXMLRPCRequestHandler

   # Restrict to a particular path.
   class RequestHandler(SimpleXMLRPCRequestHandler):
       rpc_paths = ('/RPC2',)

   # Create server
   server = SimpleXMLRPCServer(("localhost", 8000),
                               requestHandler=RequestHandler)
   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()

The following client code will call the methods made available by the
preceding server:

   import xmlrpclib

   s = xmlrpclib.ServerProxy('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()

The following "SimpleXMLRPCServer" example is included in the module
*Lib/SimpleXMLRPCServer.py*:

   server = SimpleXMLRPCServer(("localhost", 8000))
   server.register_function(pow)
   server.register_function(lambda x,y: x+y, 'add')
   server.register_multicall_functions()
   server.serve_forever()

This demo server can be run from the command line as:

   python -m SimpleXMLRPCServer

Example client code which talks to the above server is included with
*Lib/xmlrpclib.py*:

   server = ServerProxy("http://localhost:8000")
   print server
   multi = MultiCall(server)
   multi.pow(2, 9)
   multi.add(5, 1)
   multi.add(24, 11)
   try:
       for response in multi():
           print response
   except Error, v:
       print "ERROR", v

And the client can be invoked directly using the following command:

   python -m xmlrpclib


20.24.2. CGIXMLRPCRequestHandler
================================

The "CGIXMLRPCRequestHandler" class can be used to  handle XML-RPC
requests sent to Python CGI scripts.

CGIXMLRPCRequestHandler.register_function(function[, name])

   Register a function that can respond to XML-RPC requests. If
   *name* is given, it will be the method name associated with
   function, otherwise *function.__name__* will be used. *name* can be
   either a normal or Unicode string, and may contain  characters not
   legal in Python identifiers, including the period character.

CGIXMLRPCRequestHandler.register_instance(instance)

   Register an object which is used to expose method names  which have
   not been registered using "register_function()". If  instance
   contains a "_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 "_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.

CGIXMLRPCRequestHandler.register_introspection_functions()

   Register the XML-RPC introspection functions  "system.listMethods",
   "system.methodHelp" and  "system.methodSignature".

CGIXMLRPCRequestHandler.register_multicall_functions()

   Register the XML-RPC multicall function "system.multicall".

CGIXMLRPCRequestHandler.handle_request([request_text = None])

   Handle an XML-RPC request. If *request_text* is given, it should be
   the POST data provided by the HTTP server,  otherwise the contents
   of stdin will be used.

Example:

   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()
