I've read that WebSockets work on iOS 4.2 and above. And I can verify that there is indeed a WebSocket object. But I can't find a single working WebSocket example that works on the phone.
For example http://yaws.hyber.org/websockets_example.yaws will crash the Mobile Safari app. Has anyone got WebSockets working successfully on the phone?
I may have found the solution. Mobile Safari only crashes with websockets when you have setup a proxy over wifi.
It is supported, but bear in mind regarding the standard that iOS Safari browser implements, it is not RFC 6455, but HyBi-00/Hixie-76.
You can test as well using this browser: http://websocketstest.com/
As well check this great post that have most of info regarding versions: https://stackoverflow.com/a/2700609/1312722
OBS!, this is an old answer. I have checked through the webpage mentioned in this post combined with browserstack.com:
All using RFC 6455
I had a similar problem and even looked to this post to find a fix for it. For me, it had nothing to do with being on a wifi connection. It appears to be a bug in the iOS implementation of websockets (even up to the current version 5.1). Turning on a bunch of XCode's debugging I found that it has something to do with memory management because I would get something along the lines of "message sent to a deallocated instance." Most likely there was an object that didn't have the correct reference count and was cleaned up way too early.
This blog has a lot of great information about the symptoms of the problem and how to debug it, but doesn't have a workaround: http://dalelane.co.uk/blog/?p=1652
Eventually though, I found this workaround, and my app has almost entirely stopped crashing now.
me = this // strange javascript convention
this.socket = new WebSocket(url);
// put onmessage function in setTimeout to get around ios websocket crash
this.socket.onmessage = function(evt) { setTimeout(function() {me.onMessageHandler(evt);}, 0); };
I got them working on Chrome and Safari, iPhone and iPad (and other mobile devices too, but I guess you don't mind about them). Here is the Javascript code I am using :
<script language="javascript" type="text/javascript">
var wsUri = document.URL.replace("http", "ws");
var output;
var websocket;
function init()
{
output = document.getElementById("output");
wsConnect();
}
function wsConnect()
{
console.log("Trying connection to " + wsUri);
try
{
output = document.getElementById("output");
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)
};
}
catch (e)
{
console.log("Exception " + e.toString());
}
}
function onOpen(evt)
{
alert("Connected to " + wsUri);
}
function onClose(evt)
{
alert("Disconnected");
}
function onMessage(evt)
{
alert('Received message : ' + evt.data);
}
function onError(evt)
{
alert("Error : " + evt.toString());
}
function doSend(message)
{
websocket.send(message);
}
window.addEventListener("load", init, false);
Sending data from client to server is done calling doSend() function. Receiving data from server also works, I've tested it from a custom C++ server.
Here is a working sample
<!DOCTYPE html>
<meta charset="utf-8" />
<head>
<title>WebSocket Test</title>
<script language="javascript" type="text/javascript">
var websocket;
function OpenWebSocket()
{
try {
websocket = new WebSocket(document.getElementById("wsURL").value);
websocket.onopen = function(evt) { onOpen(evt) };
websocket.onclose = function(evt) { onClose(evt) };
websocket.onmessage = function(evt) { onMessage(evt) };
websocket.onerror = function(evt) { onError(evt) };
}
catch(err) {
writeToScreen(err.message);
}
}
function CloseWebSocket()
{
websocket.close();
}
function FindWebSocketStatus()
{
try {
if (websocket.readyState == 1){
writeToScreen("Websocket connection is in open state")
}
else if (websocket.readyState == 0){
writeToScreen("Websocket connection is in connecting state")
}
else{
writeToScreen("Websocket connection is in close state")
}
}
catch(err) {
writeToScreen(err.message);
}
}
function FindWebSocketBufferedAmount(){
try {
writeToScreen(websocket.bufferedAmount)
}
catch(err) {
writeToScreen(err.message);
}
}
function SendMessageThroughSocket(){
doSend(document.getElementById("wsMessage").value);
}
function onOpen(evt)
{
writeToScreen("Socket Connection Opened");
}
function onClose(evt)
{
writeToScreen("Socket Connection Closed");
}
function onMessage(evt)
{
writeToScreen('<span style="color: blue;">SERVER RESPONSE: ' + evt.data+'</span>');
}
function onError(evt)
{
writeToScreen('<span style="color: red;">ERROR:</span> ' + evt.data);
}
function doSend(message)
{
try{
writeToScreen("CLIENT SENT: " + message);
websocket.send(message);
}
catch(err) {
writeToScreen(err.message);
}
}
function writeToScreen(message)
{
var output = document.getElementById("output");
var pre = document.createElement("p");
pre.style.wordWrap = "break-word";
pre.innerHTML = message;
output.appendChild(pre);
}
</script>
</title>
</head>
<body>
<table>
<tr>
<td>
WebSocket URL
</td>
<td>
<input type="text" id="wsURL" value="ws://echo.websocket.org/"/>
</td>
</tr>
<tr>
<td>
WebSocket Message
</td>
<td>
<input type="text" id="wsMessage" value="Hi"/>
</td>
</tr>
<tr>
<td colspan="2" style="text-align:left;">
<input type="button" value="Open Socket Connection" onclick="OpenWebSocket();"/>
</td>
</tr>
<tr>
<td colspan="2" style="text-align:left;">
<input type="button" value="Send Message" onclick="SendMessageThroughSocket();"/>
</td>
</tr>
<tr>
<td colspan="2" style="text-align:left;">
<input type="button" value="Close Socket Connection" onclick="CloseWebSocket();"/>
</td>
</tr>
<tr>
<td colspan="2" style="text-align:left;">
<input type="button" value="Find Socket Status" onclick="FindWebSocketStatus();"/>
</td>
</tr>
<tr>
<td colspan="2" style="text-align:left;">
<input type="button" value="Find Socket Buffered Amount" onclick="FindWebSocketBufferedAmount();"/>
</td>
</tr>
</table>
<div id="output"></div>
</body>
</html>
Creating your own socket server is also simple Just install the Node.js and socket.io then proceed to install web socket via npm
#!/usr/bin/env node
var WebSocketServer = require('websocket').server;
var http = require('http');
var server = http.createServer(function(request, response) {
console.log((new Date()) + ' Received request for ' + request.url);
response.writeHead(404);
response.end();
});
server.listen(8888, function() {
console.log((new Date()) + ' Server is listening on port 8888');
});
wsServer = new WebSocketServer({
httpServer: server,
// You should not use autoAcceptConnections for production
// applications, as it defeats all standard cross-origin protection
// facilities built into the protocol and the browser. You should
// *always* verify the connection's origin and decide whether or not
// to accept it.
autoAcceptConnections: false
});
function originIsAllowed(origin) {
// put logic here to detect whether the specified origin is allowed.
return true;
}
wsServer.on('request', function(request) {
if (!originIsAllowed(request.origin)) {
// Make sure we only accept requests from an allowed origin
request.reject();
console.log((new Date()) + ' Connection from origin ' + request.origin + ' rejected.');
return;
}
var connection = request.accept();
console.log((new Date()) + ' Connection accepted.');
connection.on('message', function(message) {
if (message.type === 'utf8') {
console.log('Received Message: ' + message.utf8Data);
connection.sendUTF('Message received at server:'+message.utf8Data);
}
else if (message.type === 'binary') {
console.log('Received Binary Message of ' + message.binaryData.length + ' bytes');
connection.sendBytes(message.binaryData);
}
});
connection.on('close', function(reasonCode, description) {
console.log((new Date()) + ' Peer ' + connection.remoteAddress + ' disconnected.');
});
});
save the above file as .js and run it like node filename.js from terminal or command prompt
The above file is like we have first created a http server using node then we're passing the created http server instance to Websocketserver then subsequently to Socket.iO instance
I was debugging a similar issue and found that if you have used https to get the web page iOS will trap if you use the pass a the "ws:" protocol into WebSocket. If you use "wss:" everything will work and there will be no traps.
