Add @expect_json to help with parsing JSON request

common/djangoapps/util/json_request.py

+from functools import wraps
+import copy
+import json
+
+def expect_json(view_function):
+    @wraps(view_function)
+    def expect_json_with_cloned_request(request, *args, **kwargs):
+        if request.META['CONTENT_TYPE'] == "application/json":
+            cloned_request = copy.copy(request)
+            cloned_request.POST = cloned_request.POST.copy()
+            cloned_request.POST.update(json.loads(request.raw_post_data))
+            return view_function(cloned_request, *args, **kwargs)
+        else:
+            return view_function(request, *args, **kwargs)
+
+    return expect_json_with_cloned_request