+
+
+class JSONEncoder(json.JSONEncoder):
+ def default(self, obj):
+ if isinstance(obj, datetime.datetime):
+ return obj.strftime('%Y-%m-%d %H:%M:%S')
+ elif isinstance(obj, datetime.date):
+ return obj.strftime('%Y-%m-%d')
+ elif isinstance(obj, datetime.time):
+ return obj.strftime('%H:%M:%S')
+ return json.JSONEncoder.default(self, obj)
+
+
+def dumps(data):
+ return JSONEncoder().encode(data)
+
+
+def loads(str):
+ return json.loads(str, encoding=settings.DEFAULT_CHARSET)
+
+
+class JSONField(models.TextField):
+ def db_type(self):
+ return 'text'
+
+ def get_internal_type(self):
+ return 'TextField'
+
+ def pre_save(self, model_instance, add):
+ value = getattr(model_instance, self.attname, None)
+ return dumps(value)
+
+ def contribute_to_class(self, cls, name):
+ super(JSONField, self).contribute_to_class(cls, name)
+ signals.post_init.connect(self.post_init, sender=cls)
+
+ def get_json(model_instance):
+ return dumps(getattr(model_instance, self.attname, None))
+ setattr(cls, 'get_%s_json' % self.name, get_json)
+
+ def set_json(model_instance, json):
+ return setattr(model_instance, self.attname, loads(json))
+ setattr(cls, 'set_%s_json' % self.name, set_json)
+
+ def post_init(self, **kwargs):
+ instance = kwargs.get('instance', None)
+ value = self.value_from_object(instance)
+ if (value):
+ setattr(instance, self.attname, loads(value))
+ else:
+ setattr(instance, self.attname, None)