# jsonrpc.py
# original code: http://trac.pyworks.org/pyjamas/wiki/DjangoWithPyJamas
# also from: http://www.pimentech.fr/technologies/outils
from django.utils import simplejson
from django.http import HttpResponse
import sys
# JSONRPCService and jsonremote are used in combination to drastically
# simplify the provision of JSONRPC services. use as follows:
#
# jsonservice = JSONRPCService()
#
# @jsonremote(jsonservice)
# def test(request, echo_param):
# return "echoing the param back: %s", echo_param
#
# dump jsonservice into urlpatterns:
# (r'^service1/$', 'djangoapp.views.jsonservice'),
def response(id, result):
return HttpResponse(simplejson.dumps({'version': '1.1', 'id':id,
'result':result, 'error':None}))
def error(id, code, message):
return HttpResponse(simplejson.dumps({'id': id, 'version': '1.1',
'error': {'name': 'JSONRPCError',
'code': code,
'message': message
}
}))
class JSONRPCService:
def __init__(self, method_map=None):
self.method_map = method_map or {}
def add_method(self, name, method):
self.method_map[name] = method
def __call__(self, request, extra=None):
# We do not yet support GET requests, something pyjamas does
# not use anyways.
data = simplejson.loads(request.raw_post_data)
# Altered to forward the request parameter when a member method
# is invocated <julien@pimentech.net>
id, method, params = data["id"],data["method"],[request,]+data["params"]
if method in self.method_map:
try:
result = self.method_map[method](*params)
return response(id, result)
except BaseException:
etype, eval, etb = sys.exc_info()
return error(id, 100, '%s: %s' %(etype.__name__, eval))
except:
etype, eval, etb = sys.exc_info()
return error(id, 100, 'Exception %s: %s' %(etype, eval))
else:
return error(id, 100, 'method "%s" does not exist' % method)
def jsonremote(service):
"""Make JSONRPCService a decorator so that you can write :
from jsonrpc import JSONRPCService
chatservice = JSONRPCService()
@jsonremote(chatservice, 'login')
def login(request, user_name):
(...)
"""
def remotify(func):
if isinstance(service, JSONRPCService):
service.add_method(func.__name__, func)
else:
emsg = 'Service "%s" not found' % str(service.__name__)
raise NotImplementedError, emsg
return func
return remotify
# This provides a mechanism for turning Django Forms into JSONRPC
# Services. If you have an existing Django app which makes prevalent
# use of Django Forms it will save you rewriting the app.
# use as follows:
#
# class SimpleForm(forms.Form):
# testfield = forms.CharField(max_length=100)
#
# class SimpleForm2(forms.Form):
# testfield = forms.CharField(max_length=20)
#
# processor = FormProcessor({'processsimpleform': SimpleForm,
# 'processsimpleform2': SimpleForm2})
#
# this will result in a JSONRPC service being created with two
# RPC functions. dump "processor" into urlpatterns to make it
# part of the app:
# (r'^formsservice/$', 'djangoapp.views.processor'),
from django import forms
def builderrors(form):
d = {}
for error in form.errors.keys():
if error not in d:
d[error] = []
for errorval in form.errors[error]:
d[error].append(unicode(errorval))
return d
class FormProcessor(JSONRPCService):
def __init__(self, forms, _formcls=None):
if _formcls is None:
JSONRPCService.__init__(self)
for k in forms.keys():
s = FormProcessor({}, forms[k])
self.add_method(k, s.__process)
#self.add_method(k, s)
else:
JSONRPCService.__init__(self, forms)
self.formcls = _formcls
def __process(self, request, params):
f = self.formcls(params)
if f.is_valid():
#do stuff
return {'success':True}
else:
return {'success':False, 'errors': builderrors(f)}
# The following is incredibly convenient for saving vast amounts of
# coding, avoiding doing silly things like this:
# jsonresult = {'field1': djangoobject.field1,
# 'field2': djangoobject.date.strftime('%Y.%M'),
# ..... }
#
# The date/time flatten function is there because JSONRPC doesn't
# support date/time objects or formats, so conversion to a string
# is the most logical choice. pyjamas, being python, can easily
# be used to parse the string result at the other end.
#
# use as follows:
#
# jsonservice = JSONRPCService()
#
# @jsonremote(jsonservice)
# def list_some_model(request, start=0, count=10):
# l = SomeDjangoModelClass.objects.filter()
# res = json_convert(l[start:end])
#
# @jsonremote(jsonservice)
# def list_another_model(request, start=0, count=10):
# l = AnotherDjangoModelClass.objects.filter()
# res = json_convert(l[start:end])
#
# dump jsonservice into urlpatterns to make the two RPC functions,
# list_some_model and list_another_model part of the django app:
# (r'^service1/$', 'djangoapp.views.jsonservice'),
from django.core.serializers import serialize
import datetime
from datetime import date
def dict_datetimeflatten(item):
d = {}
for k, v in item.items():
k = str(k)
if isinstance(v, datetime.date):
d[k] = str(v)
elif isinstance(v, dict):
d[k] = dict_datetimeflatten(v)
else:
d[k] = v
return d
def json_convert(l, fields=None):
res = []
for item in serialize('python', l, fields=fields):
res.append(dict_datetimeflatten(item))
return res
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