How to decode Json Format for the proto files using Protobuf.js?

Question

I'm trying to understand, how does the ProtoBuf.js work?

ProtoBuf - https://github.com/dcodeIO/ProtoBuf.js

My proto file gameSetting.proto looks like:

message GameSettings {
    required string gameName = 1;
    repeated Category categories = 2;
}

message Category {
    required int32 categoryId = 1;
    required string categoryAbbreviation = 2;
    required string categoryName = 3;
    required string numberInSquad = 4;
    required string numberInTeam = 5;
    required string captain = 6;
}

Here, I am implementing JavaScript code with decoding and encoding of data:

  var ProtoBuf = dcodeIO.ProtoBuf;
  var protoURL = '../_doc/protobuf/gameSettings.proto';
  var dataURL = '../xmlapi?type=game-settings&competitionid=1&outputtype=text';
  var builder = ProtoBuf.loadProtoFile( protoURL, function(err, builder) {

// WE CAN ALSO TRY USING JSON FORMAT FOR THE PROTO FILES:
// https://github.com/dcodeIO/ProtoBuf.js/wiki/Builder#using-json-without-the-proto-parser

// encoding test
  var GS_build = builder.build( 'GameSettings' );
  var GS = new GS_build({
  "gameName": "games Test 2015",
  "categories": [{ 
     "categoryId": 1,                                                             
     "categoryAbbreviation": "GK",
     "categoryName": "Goalkeeper",
     "numberInSquad": "2-2",
     "numberInTeam": "1-1",
     "captain": "0-1"
  }]
});


// encode various types to test
  var GS_buffer = GS.encode();
  var GS_base64 = GS.encode64(); // this looks like something to use with AJAX
  var GS_arrayBuffer = GS_buffer.toArrayBuffer();

// decoding test
  var GS_buffer_decoded = GS_build.decode( GS_buffer );
  var GS_buffer_decoded_raw = GS_buffer_decoded.toRaw();
  var GS_base64_decoded = GS_build.decode64( GS_base64 );
  var GS_base64_decoded_raw = GS_base64_decoded.toRaw();
  var GS_arrayBuffer_decoded = GS_build.decode( GS_arrayBuffer );
  var GS_arrayBuffer_decoded_raw = GS_arrayBuffer_decoded.toRaw();


// decoding AJAX test
  $.get( dataURL, function( data ){
  var GS = GS_build.decode( data );   
  });
});

The code // encoding test and // decoding test - works fine.

But there is some problem in the code:

var GS = GS_build.decode( data ) 

How can I fix it?

Answer 1

The API here is:

Message.decode(buffer:Uint8Array|ArrayBuffer|Buffer|string, encoding:string=)

with encoding only required if buffer is a string. Hence, to be able to decode a chunk of data, you have to make sure that it either is an ArrayBuffer/Uint8Array or, if it is a string, provide the correct encoding.

Using jQuery's $.get without any options will probably corrupt the data, though.

See also: https://github.com/dcodeIO/ProtoBuf.js/wiki/How-to-read-binary-data-in-the-browser-or-under-node.js%3F