Training Guide: Programming in HTML5 with JavaScript and CSS3 Ebook

418 CHAPTER 10 WebSocket communications

var webSocket;

$(document).ready(function () {

if (checkSupported()) {

connect();

$('#btnSend').click(doSend);

}

});

function writeOutput(message) {

var output = $("#divOutput");

output.html(output.html() + '<br />' + message);

}

function checkSupported() {

if (window.WebSocket) {

writeOutput('WebSockets supported!');

return true;

}

else {

writeOutput('WebSockets NOT supported');

$('#btnSend').attr('disabled', 'disabled');

return false;

}

}

function connect() {

webSocket = new WebSocket(wsUri);

webSocket.onopen = function (evt) { onOpen(evt) };

webSocket.onclose = function (evt) { onClose(evt) };

webSocket.onmessage = function (evt) { onMessage(evt) };

webSocket.onerror = function (evt) { onError(evt) };

}

function doSend() {

if (webSocket.readyState != webSocket.OPEN)

{

writeOutput("NOT OPEN: " + $('#txtMessage').val());

return;

}

writeOutput("SENT: " + $('#txtMessage').val());

webSocket.send($('#txtMessage').val());

}

function onOpen(evt) {

writeOutput("CONNECTED");

}

function onClose(evt) {

writeOutput("DISCONNECTED");

}

function onMessage(evt) {

writeOutput('RESPONSE: ' + evt.data);

}