Question

我正在尝试创建以下自引用EndpointsModel（_fix_up_properties()的技巧取自此处：https://groups.google.com/forum/#!topic/appengine-ndb-discuss/1FmgEVK7JNM）：

class EventFieldSchema(EndpointsModel):
  name = ndb.StringProperty(required=True)
  type = msgprop.EnumProperty(EventType, required=True)

EventFieldSchema.nested_fields = ndb.LocalStructuredProperty(EventFieldSchema,repeated=True)
EventFieldSchema._fix_up_properties()

这适用于数据存储模型，但遗憾的是，nested_fields字段不会包含在ProtoRPC消息中。我试图手动指定消息字段架构，在最后一行添加：

EventFieldSchema._message_fields_schema = ('name', 'type', 'nested_fields')

然后app-engine失败，进入循环，尝试将EventFieldSchema转换为ProtoRPC字段：

Traceback (most recent call last):
File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 240, in Handle
  handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
  handler, path, err = LoadObject(self._handler)
File "/base/data/home/runtimes/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 85, in LoadObject
  obj = __import__(path[0])
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/main.py", line 3, in <module>
  from er.api.event import EventRegistryApi
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/er/api/event.py", line 17, in <module>
  class EventRegistryApi(remote.Service):
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/er/api/event.py", line 23, in EventRegistryApi
  name='%s.insert' % RESOURCE_NAME)
File "/base/data/home/runtimes/python27/python27_lib/versions/third_party/protorpc-1.0/protorpc/util.py", line 170, in positional_wrapper
  return wrapped(*args, **kwargs)
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/model.py", line 1359, in method
  kwargs[REQUEST_MESSAGE] = cls.ProtoModel(fields=request_fields)
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/model.py", line 1031, in ProtoModel
  allow_message_fields=allow_message_fields)
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/model.py", line 969, in _MessageFields
  proto_attr = to_proto(prop, field_index)
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/utils.py", line 137, in StructuredPropertyToProto
  property_proto = property_proto_method()
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/model.py", line 1031, in ProtoModel
  allow_message_fields=allow_message_fields)
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/model.py", line 969, in _MessageFields
  proto_attr = to_proto(prop, field_index)
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/utils.py", line 137, in StructuredPropertyToProto
  property_proto = property_proto_method()
File "/base/data/home/apps/s~project/eventregistry:dev.380885914276541023/endpoints_proto_datastore/ndb/model.py", line 1031, in ProtoModel

这是EndpointsModel中的错误吗？什么是定义自引用EndpointsModels的“正确”方法？

Answer 1

在自引用EndpointsModel时遇到同样的问题：

class UnitsProtoModel(EndpointsModel):
  """ ProtoRPC Model for storing/retrieving a unit. """

  _message_fields_schema = ('id', 'uic', 'parent_id', 'branch_id', 'name')

  uic = ndb.StringProperty(required=True)
  parent_id = ndb.StringProperty(required=True, default=None)
  branch_id = ndb.StringProperty(required=True)
  name = ndb.StringProperty(required=True)
  abbreviated_name = ndb.StringProperty(default="")
  flagged = ndb.BooleanProperty(default=False)
  message = ndb.StringProperty(default="")
  unit_created_at = ndb.DateTimeProperty(auto_now_add=True)


class UnitsCollection(EndpointsModel):
  items = messages.MessageField(UnitsProtoModel, 1, repeated=True)

错误消息： `file“/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle / Contents / Resources / google_appengine / lib / protorpc-1.0 / protorpc / util.py”，第170行，位于position_wrapper

return wrapped(*args, **kwargs)

文件“/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/lib/protorpc-1.0/protorpc/messages.py”，第1531行，在 init < /强>

raise FieldDefinitionError('Invalid message class: %s' % message_type)

FieldDefinitionError：无效的消息类：

UnitsProtoModel<abbreviated_name=StringProperty('abbreviated_name', default=''), branch_id=StringProperty('branch_id', required=True), flagged=BooleanProperty('flagged', default=False), message=StringProperty('message', default=''), name=StringProperty('name', required=True), owner=UserProperty('owner'), parent_id=StringProperty('parent_id', required=True), uic=StringProperty('uic', required=True), unit_created_at=DateTimeProperty('unit_created_at', auto_now_add=True)>`

如何创建自引用EndpointsModel

1 个答案: