+
+
+def stringify_keys(dictionary):
+ return dict((keyword.encode('ascii'), value)
+ for keyword, value in dictionary.iteritems())
+
+
+def json_encode(obj, sort_keys=True, ensure_ascii=False):
+ return json.dumps(obj, sort_keys=sort_keys, ensure_ascii=ensure_ascii)
+
+
+def json_decode(obj):
+ return json.loads(obj)
+
+
+def json_decode_fallback(value):
+ try:
+ return json_decode(value)
+ except ValueError:
+ return value
+
+
+class AjaxError(Exception):
+ pass
+
+
+def ajax(login_required=True, method=None, template=None, permission_required=None):
+ def decorator(fun):
+ @wraps(fun)
+ def ajax_view(request):
+ kwargs = {}
+ request_params = None
+ if method == 'post':
+ request_params = request.POST
+ elif method == 'get':
+ request_params = request.GET
+ fun_params, xx, fun_kwargs, defaults = getargspec(fun)
+ if defaults:
+ required_params = fun_params[1:-len(defaults)]
+ else:
+ required_params = fun_params[1:]
+ missing_params = set(required_params) - set(request_params)
+ if missing_params:
+ res = {
+ 'result': 'missing params',
+ 'missing': ', '.join(missing_params),
+ }
+ else:
+ if request_params:
+ request_params = dict(
+ (key, json_decode_fallback(value))
+ for key, value in request_params.iteritems()
+ if fun_kwargs or key in fun_params)
+ kwargs.update(stringify_keys(request_params))
+ res = None
+ if login_required and not request.user.is_authenticated():
+ res = {'result': 'logout'}
+ if (permission_required and
+ not request.user.has_perm(permission_required)):
+ res = {'result': 'access denied'}
+ if not res:
+ try:
+ res = fun(request, **kwargs)
+ if res and template:
+ res = {'html': render_to_string(template, res, RequestContext(request))}
+ except AjaxError as e:
+ res = {'result': e.args[0]}
+ if 'result' not in res:
+ res['result'] = 'ok'
+ return HttpResponse(json_encode(res), content_type='application/json; charset=utf-8',
+ status=200 if res['result'] == 'ok' else 400)
+
+ return ajax_view
+
+ return decorator