Added get_proxy_object helper to filefields (#391)

tests/fields/file_tests.py

@@ -455,5 +455,31 @@ class FileTest(unittest.TestCase):
         self.assertEqual(1, TestImage.objects(Q(image1=grid_id)
                                               or Q(image2=grid_id)).count())
 
+    def test_complex_field_filefield(self):
+        """Ensure you can add meta data to file"""
+
+        class Animal(Document):
+            genus = StringField()
+            family = StringField()
+            photos = ListField(FileField())
+
+        Animal.drop_collection()
+        marmot = Animal(genus='Marmota', family='Sciuridae')
+
+        marmot_photo = open(TEST_IMAGE_PATH, 'rb')  # Retrieve a photo from disk
+
+        photos_field = marmot._fields['photos'].field
+        new_proxy = photos_field.get_proxy_obj('photos', marmot)
+        new_proxy.put(marmot_photo, content_type='image/jpeg', foo='bar')
+        marmot_photo.close()
+
+        marmot.photos.append(new_proxy)
+        marmot.save()
+
+        marmot = Animal.objects.get()
+        self.assertEqual(marmot.photos[0].content_type, 'image/jpeg')
+        self.assertEqual(marmot.photos[0].foo, 'bar')
+        self.assertEqual(marmot.photos[0].get().length, 8313)
+
 if __name__ == '__main__':
     unittest.main()