CODEWITHSUNDEEP
flutterdartsocket.io
Zero Live
Zero Live

Reputation: 1843

How to send files to node.js server using flutter?

I am using socket_io_client package to communicate with nodejs socket server. Here is my socket configuration for flutter:

socket = IO.io(SocketUrl.url, <String, dynamic>{
      'transports': ["websocket"],
      "autoConnect": false
    });
    socket.connect();
    socket.on('connect', (_) {
      print('socket connected to server');
    });
    socket.on('newMessage', (message) {
      print(message);
    });
    socket.on('event', (data) => print(data));
    socket.on('disconnect', (_) => print('disconnect'));
  }

Here is logic for file sending:

const data = {
            userId: currentUser.id,
            file: file.name
          };
          const stream = ss.createStream();
          ss(socket).emit("send-file", stream, data);
          ss.createBlobReadStream(file).pipe(stream);

This is how it would be done from a node client. I need to write dart version of above code. I saw that quiver package has async functions to create streambuffer but I don't know how to implement that for this particular application.

Edited:

 void onSendFile(file, data) async {
    final isFile = File(file);
    var buffer = isFile.openRead();
    //socket.emit("send-file",[buffer,data]);
    socket.emitWithBinary("send-file", [buffer, data]);
  }

Upvotes: 2

Views: 3006

Answers (2)

kishea
kishea

Reputation: 637

You can use package https://pub.dev/packages/web_socket_channel
See an Official example https://flutter.dev/docs/cookbook/networking/web-sockets
convert file to bytes and sink to the stream

final bytes = await myFile.readAsBytes();

main() async {
  var channel = IOWebSocketChannel.connect("ws://localhost:1234");
  channel.stream.listen((message) {
    channel.sink.add(bytes);
    channel.sink.close(status.goingAway);
  });
}

Upvotes: 0

Yaobin Then
Yaobin Then

Reputation: 2832

Reading from the API references and issue on socket_io_client's repo, you should be able to send binaries with socket.emitWithBinary.

Assuming you already have a mean to get on a File, you'd most likely able to do this

final myFile = File('file.txt');
final bytes = await myFile.readAsBytes();

socket.emitWithBinary('send-file', bytes);

Update

From the JS version of socket-io client, the emit function is able to take multiple arguments, which in the end is converted to an array, and so I presumed that you'll be able to achieve the same thing by passing an array to emitWithBinary or emit

Note

Seeing that your JS version doesn't contain any binary flags, you might want to try emit instead.

socket.emit(
  'send-file',
  [
    123,
    {
      'userId': currentUser.id,
      'file': file.name,
    },
  ],
);

Upvotes: 2

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