How to load a proto file with imports

Question

I am using the dcodeIO/protobuf.js lib (version 6.8.4) to parse protobuf messages in the browser. I can make it work with simple proto files, as long as another proto file is not imported.

Importing other proto files in the main one breaks everything.

This is what I have:

• File struct

  - assets/
      |-api/
      |    |-v1/
      |    |    |-messageB.proto
      |    |-messageA.proto
  - foo.js
  

• messageA.proto

  syntax = "proto3";
  package com.assets.api;
  import "api/v1/messageB.proto";
  
  message MessageA{
      MessageB foo = 0;
  }
  

• messageB.proto

  syntax = "proto3";
  package com.assets.api.v1;
  
  message MessageB {
      string bar= 0;
  }
  

• with 6.8.4:

  var MessageProto = null;
  protobuf.load({root:"assets", file:"api/messageA.proto"}, function (err, root) {
      if (root) { MessageAProto = root.lookupType("com.assets.api.MessageA");
  }});
  data = MessageProto .decode(rawData);
  

.

    Error: no such type

at Root.lookupType (http://localhost:63342/xx/build/app/vendor/protobuf/dist/protobuf.js:3463:15)
at http://localhost:63342/xx/build/app/src/app/asset/asset.module.js:320:53
at finish (http://localhost:63342/xx/build/app/vendor/protobuf/dist/protobuf.js:5212:9)
at Root.load (http://localhost:63342/xx/build/app/vendor/protobuf/dist/protobuf.js:5316:9)
at Object.load (http://localhost:63342/xx/build/app/vendor/protobuf/dist/protobuf.js:2547:17)
at new <anonymous> (http://localhost:63342/xx/build/app/src/app/asset/asset.module.js:316:22)
at Object.instantiate (http://localhost:63342/xx/build/app/vendor/angular/angular.js:4786:14)
at $controller (http://localhost:63342/xx/build/app/vendor/angular/angular.js:10607:28)
at Object.<anonymous> (http://localhost:63342/xx/build/app/vendor/angular-ui-router/release/angular-ui-router.js:4081:28)
at http://localhost:63342/xx/build/app/vendor/angular/angular.js:1259:18

• with 5.0:

  var MessageProto = null;
  dcodeIO.ProtoBuf.convertFieldsToCamelCase = true;
  dcodeIO.ProtoBuf.loadProtoFile({root: "assets", file: "api/messageA.proto"}, function (err, builder) {
      if (builder) { MessageProto = builder.build("com.assets.api.MessageA");
   }});
  data = MessageProto .decode(rawData);
  

  .

  OK
  

Symonds

Answer 1

You need to check first the protobuf.load is loaded your component. If not loaded it won't work.

You can change the load to loadSync

    var MessageProto = null;
    protobuf.loadSync({root:"assets", file:"api/messageA.proto"}, function(err, root) {
        if (root) { MessageAProto = root.lookupType("com.assets.api.MessageA");
    }});

data = MessageProto .decode(rawData);

Optionally you can use static method.

    import { AwesomeMessage } from "./bundle.js";

    // example code
    let message = AwesomeMessage.create({ awesomeField: "hello" });
    let buffer  = AwesomeMessage.encode(message).finish();
    let decoded = AwesomeMessage.decode(buffer);

To create static file use

pbjs -t json-module -w commonjs -o bundle.js file1.proto file2.proto

Escalade