javascript - 如何通过导入加载 proto 文件

Question

我正在使用dcodeIO/protobuf.js lib(版本 6.8.4)用于在浏览器中解析 protobuf 消息。 只要不导入另一个原始文件，我就可以让它使用简单的原始文件。

在主文件中导入其他原始文件会破坏一切。

这就是我所拥有的:

• 文件结构

  - 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;
  }
  

• 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

• 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
  

Answer 1

您需要首先检查 protobuf.load 是否已加载您的组件。如果没有加载，它将无法工作。

您可以将负载更改为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);

您可以选择使用静态方法。

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

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

要创建静态文件，请使用

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