Adds json module providing a JSONEnocder

Author: wcdolphin

flask_mongoengine/json.py

@@ -0,0 +1,37 @@
+from flask.json import JSONEncoder
+from bson import json_util
+from mongoengine.base import BaseDocument
+from mongoengine.queryset.base import BaseQuerySet
+
+class MongoEngineJSONEncoder(JSONEncoder):
+    '''
+    A JSONEncoder which provides serialization of MongoEngine
+    documents and querysets.
+    '''
+    def default(self,obj):
+        if isinstance(obj,BaseDocument):
+            return json_util._json_convert(obj.to_mongo())
+        elif isinstance(obj,BaseQuerySet):
+            return json_util._json_convert(obj.as_pymongo())
+        return JSONEncoder.default(self, obj)
+
+
+def overide_json_encoder(app):
+    '''
+    A function to dynamically create a new MongoEngineJSONEncoder class
+    based upon a custom base class.
+    This function allows us to combine MongoEngine serialization with
+    any changes to Flask's JSONEncoder which a user may have made
+    prior to calling init_app.
+
+    NOTE: This does not cover situations where users override
+    an instance's json_encoder after calling init_app. 
+    '''
+    class MongoEngineJSONEncoder(app.json_encoder):
+        def default(self,obj):
+            if isinstance(obj,BaseDocument):
+                return json_util._json_convert(obj.to_mongo())
+            elif isinstance(obj,BaseQuerySet):
+                return json_util._json_convert(obj.as_pymongo())
+            return app.json_encoder.default(self, obj)
+    app.json_encoder = MongoEngineJSONEncoder