How send arraybuffer as binary via Websocket?

arraybuffer, binary, file-upload, javascript, websocket

Solution

Gecko11.0 `ArrayBuffer` send and receive support for `binary` `data` has been implemented.

connection = new WebSocket( 'ws://localhost:1740' );
connection.binaryType = "arraybuffer";
connection.onopen = onopen;
connection.onmessage = onmessage;
connection.onclose = onclose;
connection.onerror = onerror;

sending `Binary data`:

function sendphoto() {
    imagedata = context.getImageData( 0, 0, imagewidth, imageheight );
    var canvaspixelarray = imagedata.data;
    var canvaspixellen = canvaspixelarray.length;
    var bytearray = new Uint8Array( canvaspixellen );
    for ( var i = 0; i < canvaspixellen; ++i ) {
        bytearray[i] = canvaspixelarray[i];
    }
    connection.send( bytearray.buffer );
    context.fillStyle = '#ffffff';
    context.fillRect( 0, 0, imagewidth, imageheight );
}

Recieving `Binary Data`:

if ( event.data instanceof ArrayBuffer ) {
    var bytearray = new Uint8Array( event.data );
    var tempcanvas = document.createElement( 'canvas' );
    tempcanvas.height = imageheight;
    tempcanvas.width = imagewidth;
    var tempcontext = tempcanvas.getContext( '2d' );
    var imgdata = tempcontext.getImageData( 0, 0, imagewidth, imageheight );
    var imgdatalen = imgdata.data.length;
    for ( var i = 8; i < imgdatalen; i++ ) {
        imgdata.data[i] = bytearray[i];
    }
    tempcontext.putImageData( imgdata, 0, 0 );
    var img = document.createElement( 'img' );
    img.height = imageheight;
    img.width = imagewidth;
    img.src = tempcanvas.toDataURL();
    chatdiv.appendChild( img );
    chatdiv.innerHTML = chatdiv.innerHTML + "<br />";
}

Problem

I am working on a project with Mozilla Europe. In this project, I use websocket by Worlize (server-side) and Mozilla (client side), Node.js to try to upload files from a client to a server. My present goal is to send a `arraybuffer` of the file to the server. Create the arraybuffer and send it is fine. But my server tells me that `arraybuffer` is a utf8 message and not a binary message. Do I misunderstand something? If not, how can i correct that? Client side: ``` reader = new FileReader(); reader.readAsArrayBuffer(file); reader.onload = function(e) { connection.send(e.target.result); }; ``` Server side: ``` ws.on('message', function(message,flags) { if (!flags.binary) { //some code } else { console.log('It\'s a binary'); } ``` I try with `Blob` too, same result. The binary part is invisible.

Original source