From Blob to ByteBuffer

[Ernest Micklei]

Hi,

In Dart, I am using a websocket to receive binary data (protobuf encoded).

From the MessageEvent, I receive an instance of Blob.

How can I access its bytes in order to unmarshall my message? (for that I need a ByteBuffer or Uint8List)

Thanks

^ Ernest

[Günter Zöchbauer]

I think the code example in this question should work for your use case too

http://stackoverflow.com/questions/22889356

[Ernest Micklei]

Thx, based on that I figured to set the binaryType of the socket:

ws.binaryType = "arraybuffer";

Now, I get an List<int> (Uint8List) from the MessageEvent data.

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^ Ernest Micklei

http://ernestmicklei.com

[Ernest Micklei]

I noticed that running the app inside a browser (after dart2js 1.2.0) 

the MessageEvent data is a ByteBuffer and causes runtime errors somewhere. 

I am not sure whether it is a Dart protobuf issue or dart2js. Suggestions anybody?

[Ernest Micklei]

My workaround:

    if (e.data is Uint8List) {

      // Dartium

      mm = new MyMessage.fromBuffer(e.data);

    } else {

      // Javascript

      ByteBuffer buf = e.data as ByteBuffer;

      mm = new MyMessage.fromBuffer(new Uint8List.view(buf));

[Emily Fortuna]

Hi Ernest,

You're right, that looks like a bug in the dart:html library. I've filed a bug about it here: https://code.google.com/p/dart/issues/detail?id=19364

Emily