NOTE: All credit for this code goes to Crast in irc.freenode.net:#django...

This uses SimpleXMLRPCDispatcher which is part of the standard Python lib in 2.4 (And possibly earlier versions).


In discussing ways of handling XML-RPC for Django, I realised I really needed a way to do it without patching Django's code.  Crast in #django came up with a great solution, which I have modified and tweaked a bit.

I've included it here.  Feel free to fiddle with it and make it your own ... All this code is '''post-mr'''

Any crappy & garbage code is completely mine; I'm still learning Python so bear with me.  The hacks I added for self-documentation output are just that; any improvements to them would probably be a good thing.

First, setup your urls.py to map an XML-RPC service:


{{{
#!python
urlpatterns = patterns('',
    # XML-RPC
     (r'^xml_rpc_srv/', 'yourproject.yourapp.xmlrpc.rpc_handler'),
)
}}}


Then, in the appropriate place, create a file called xmlrpc.py


{{{
#!python
# Patchless XMLRPC Service for Django
# Kind of hacky, and stolen from Crast on irc.freenode.net:#django
# Self documents as well, so if you call it from outside of an XML-RPC Client
# it tells you about itself and its methods
#
# Brendan W. McAdams <brendan.mcadams@thewintergrp.com>

# SimpleXMLRPCDispatcher lets us register xml-rpc calls w/o
# running a full XMLRPC Server.  It's up to us to dispatch data

from SimpleXMLRPCServer import SimpleXMLRPCDispatcher
from django.http import HttpResponse

# Create a Dispatcher; this handles the calls and translates info to function maps
dispatcher = SimpleXMLRPCDispatcher()


def rpc_handler(request):
	"""
	the actual handler:
	if you setup your urls.py properly, all calls to the xml-rpc service
	should be routed through here.
	If post data is defined, it assumes it's XML-RPC and tries to process as such
	Empty post assumes you're viewing from a browser and tells you about the service.
	"""

	response = HttpResponse()
	if len(request.POST):
		response.write(dispatcher._marshaled_dispatch(request.raw_post_data))
	else:
		response.write("<b>This is an XML-RPC Service.</b><br>")
		response.write("You need to invoke it using an XML-RPC Client!<br>")
		response.write("The following methods are available:<ul>")
		methods = dispatcher.system_listMethods()

		for method in methods:
			# right now, my version of SimpleXMLRPCDispatcher always
			# returns "signatures not supported"... :(
			# but, in an ideal world it will tell users what args are expected
			sig = dispatcher.system_methodSignature(method)

			# this just reads your docblock, so fill it in!
			help =  dispatcher.system_methodHelp(method)

			response.write("<li><b>%s</b>: [%s] %s" % (method, sig, help))

		response.write("</ul>")
		response.write('<a href="http://www.djangoproject.com/"><img src="http://media.djangoproject.com/img/badges/djangomade124x25_grey.gif" border="0" alt="Made with Django." title="Made with Django."></a>')

	response['Content-length'] = str(len(response.content))
	return response

def multiply(a, b):
	"""
	Multiplication is fun!
	Takes two arguments, which are multiplied together.
	Returns the result of the multiplication!
	"""
	return a*b

# you have to manually register all functions that are xml-rpc-able with the dispatcher
# the dispatcher then maps the args down.
# The first argument is the actual method, the second is what to call it from the XML-RPC side...
dispatcher.register_function(multiply, 'multiply')
}}}

That's it!

You can pretty much write a standard python function in there, just be sure to register it with the dispatcher when you're done.  

Here's a quick and dirty client example for testing:

{{{
#!python
import sys
import xmlrpclib
rpc_srv = xmlrpclib.ServerProxy("http://localhost:8000/xml_rpc_srv/")
result = rpc_srv.multiply( int(sys.argv[1]), int(sys.argv[2]))
print "%d * %d = %d" % (sys.argv[1], sys.argv[2], result)
}}}

Based on experience, I do recommend that you use Dictionaries for your args rather than long args, but I think that's personal preference (It allows named arguments and eliminates 'out of order' argument issues).

Have fun!

- [mailto:brendan.mcadams@NOSPAM.thewintergrp.com  Brendan W. McAdams <brendan.mcadams@NOSPAM.thewintergrp.com>]