CODEWITHSUNDEEP
protocol-buffersgrpc
Lin Du
Lin Du

Reputation: 102207

How to reuse fields in different message type?

Here is the content of .proto file:

syntax="proto3";

package topic;

option go_package="github.com/mrdulin/grpc-go-cnode/internal/protobufs/topic";

import "internal/protobufs/shared/user.proto";
import "internal/protobufs/reply/domain.proto";

enum Tab {
  share = 0;
  ask = 1;
  good = 2;
  job = 3;
}

message Topic {
  string id = 1;
  string author_id = 2;
  Tab tab = 3;
  string title = 4;
  string content = 5;
  shared.UserBase author = 6;
  bool good = 7;
  bool top = 8;
  int32 reply_count = 9;
  int32 visit_count = 10;
  string create_at = 11;
  string last_reply_at = 12;
}

message TopicDetail {
  string id = 1;
  string author_id = 2;
  Tab tab = 3;
  string title = 4;
  string content = 5;
  shared.UserBase author = 6;
  bool good = 7;
  bool top = 8;
  int32 reply_count = 9;
  int32 visit_count = 10;
  string create_at = 11;
  string last_reply_at = 12;
  // different fields
  repeated reply.Reply replies = 13;
  bool is_collect = 14;
}

As you can see, in Topic and TopicDetail message types, most of the fields are the same. Is there any way such as inheritance, composition(embed message type) so I can DRY?

Upvotes: 2

Views: 2857

Answers (1)

dmaixner
dmaixner

Reputation: 874

Sure, you can do something like this:

message Topic {
  string id = 1;
  string author_id = 2;
  Tab tab = 3;
  string title = 4;
  string content = 5;
  shared.UserBase author = 6;
  bool good = 7;
  bool top = 8;
  int32 reply_count = 9;
  int32 visit_count = 10;
  string create_at = 11;
  string last_reply_at = 12;
}

message TopicDetail {
  Topic topic = 1;
  repeated reply.Reply replies = 2;
  bool is_collect = 3;
}

For details you can check https://developers.google.com/protocol-buffers/docs/proto3#other or if you would like to keep them nested, you can do that too, see: https://developers.google.com/protocol-buffers/docs/proto3#nested

Upvotes: 2

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