Changes between Initial Version and Version 1 of XML-RPC

Timestamp:

May 24, 2006, 3:29:09 PM (19 years ago)

Author:

brendan.mcadams@…

Comment:

Example of how to do clean XML-RPC without patching django

XML-RPC

@@ +1 @@
+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 addded 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:
+
+
+{{{
+urlpatterns = patterns('',
+    # XML-RPC
+     (r'^xml_rpc_srv/', 'yourproject.yourapp.xmlrpc.rpc_handler'),
+)
+}}}
+
+
+Then, in the appropriate place, create a file called xmlrpc.py
+
+
+{{{
+# 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 it's 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>')
+
+        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:
+
+{{{
+import sys
+import xmlrpclib
+rpc_srv = xmlrpclib.ServerProxy("http://localhost:8000/xml_rpc_srv/")
+result = rpc_srv.multiply(sys.argv[1], 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@thewintergrp.com  Brendan W. McAdams <brendan.mcadams@thewintergrp.com>]