Django AJAX Framework

[Vladimir Pouzanov]

I've started this as SoC project, however is hasn't passed so I'm
publising the sources, maybe you'll find them useful.

I've uses Json as the transport layer. You will need Json-py library
(http://sourceforge.net/projects/json-py/). To make server-side code
you need to make a new django view:

from django.http import HttpResponse
from cmh.apps.rpc.minjson import write as JsonWrite
import re

def rpc(request):
if ('module' in request.GET) and ('function' in request.GET):
rx = re.compile('^[a-z]+$')
if rx.match(request.GET['module']):
try:
rpc_fn =
getattr(__import__('testproject.%s.rpc'%request.GET['module'],
'', '', ['']), request.GET['function'])
except ImportError, e:
return HttpResponse('module not found')

return HttpResponse(JsonWrite(rpc_fn(request)))
else:
return HttpResponse('bad module name')
else:
return HttpResponse('bad module')

This request accepts only module names from small latin chars, you
need to change regular expression ('^[a-z]+$') if you have other
module names. RPC functions are stored at modules' directories in
files rpc.py. You need to change 'testproject.%s.rpc' so that it point
to your module's rpc file, e.g. my CMS uses 'cmh.apps.%s.rpc' (all my
modules are stored in apps folder).

The client-side is handled by MochiKit.

<script type="text/javascript" src="/js/mochikit/MochiKit/Base.js"></script>
<script type="text/javascript" src="/js/mochikit/MochiKit/Async.js"></script>
<script type="text/javascript" src="/js/mochikit/MochiKit/DOM.js"></script>
<script type="text/javascript">

// Point to your rpc view
var baseURL = "http://localhost:8000/rpc/";

function processRPC(req)
{
json = evalJSONRequest(req);
for(var i in json) {
switch(json[i].action) {
case "replace":
var element = getElement(json[i].id);
element.innerHTML = json[i].value;
break;
// handle additional operations like
add_before, add_after, hide, show, etc.
}
}
}

function doRPC(mod, func, method, s_get, s_post)
{
var d;
var req = getXMLHttpRequest();
if (req.overrideMimeType) {
req.overrideMimeType("text/plain");
}
if(method == "GET") {
req.open("GET", baseURL + "?module=" + mod +
"&function=" + func + s_get, true);
d = sendXMLHttpRequest(req).addCallback(processRPC);
} else {
req.open("POST", baseURL + "?module=" + mod +
"&function=" + func + s_get, true);
d = sendXMLHttpRequest(req, s_post).addCallback(processRPC);
}
return d;
}
</script>

sample usage:
<a href="javascript: doRPC('rpc', 'test', 'GET', '&some_extra=args');">GET</a>

<a href="javascript: doRPC('rpc', 'test', 'POST', '',
'some_extra=args');">POST</a>

here's how you handle this call (testproject/rpc/rpc.py):
def test(args):
action1 = { 'action': 'replace', 'id': 'footer', 'value':
'<h1>footer changed ;)</h1>' }
action2 = { 'action': 'replace', 'id': 'content-related',
'value': '<h1>some more modifications</h1>' }
return [action1, action2]

Maybe this code doesn't look a django-way, but I'm still working on it.

--
Sincerely,
Vladimir "Farcaller" Pouzanov
http://www.hackndev.com