AttributeError: 'event_template' object attribute 'appname' is read-only and modeling questions

[Aditya Sakhuja]

I am trying to correctly model a container queue_object using protobufs. It wraps ‘args’ message object and acts as the container for ‘eventing_template’ message object.

Finally, ‘Data’ message object is extended by ‘admin’ and ‘analytics’ message object.

Couple of things I am head heavy with right now :

First, is this the best way to model this scenario ? I have my sample files below.

Second, I get an attributeerror  exception saying the attr is readonly when trying to write eventing_template message’s attr ‘appname’. 

"AttributeError: 'event_template' object attribute 'appname' is read-only"

Not sure what is the correct way to write/read eventing.appname and similar indirect references.  I am writing the client in python.

filename : queue_object.proto

   message queue_object {

      required string kwargs = 1;

       message args {

          extensions 100 to 200;

       }

      required string errors = 3;

      required string trace_id = 4;

      required string start_time = 5;

   }

filename : eventing_template.proto

import "queue_object.proto";

     message event_template {

         

message Data {

           extensions 1000 to max;

          }

         extend queue_object.args {

             required string appname = 101;

             optional int32 completion_status = 102;

             optional int32 page_number = 103;

             optional int32 result_per_page = 104;

             optional User user = 112;

             optional Data data = 116;

         }

     }

    message User {

         optional string ip = 1;

         optional string xid = 2;

         optional string loc = 3;

         optional string aid = 4;

     }

filename : admin.proto

import "event_template.proto";

message admin {

   extend event_template.Data {

       optional string content_length = 1000;

       optional string oauth_app_id = 1001;

       optional string response_code = 1002;

       optional int64 response_length = 1003;

       optional bool static = 1004;

   }

}

filename : analytics.proto

import "event_template.proto";

message analytics {

   extend event_template.Data {

       optional string content_length = 2000;

       optional string oauth_app_id = 2001;

       optional string response_code = 2002;

       optional int64 response_length = 2003;

       optional bool static = 2004;

   }

}

Would really appreciate feedback on this

Thanks,

Aditya