Reputation: 2498

WebSockets on iOS

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?

Upvotes: 22

Answers (6)

Justin Bullard

Reputation: 33

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.

Upvotes: 1

moka

Reputation: 23047

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:

iPhone4S
iPhone5
iPhone5S
iPhone6
iPhone6 Plus
iPhone6S
iPhone6S Plus

All using RFC 6455

Upvotes: 7

Durai Amuthan.H

Reputation: 32270

Here is a working sample

Web socket client

<!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>

Web Socket server

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

Upvotes: 1

Mickaël C. Guimarães

Reputation: 1112

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.

Upvotes: 2

Matt

Reputation: 1445

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); };

Upvotes: 4

probablyCorey

Reputation: 2498

I may have found the solution. Mobile Safari only crashes with websockets when you have setup a proxy over wifi.

Upvotes: 12

WebSockets on iOS

Answers (6)

Web socket client

Web Socket server

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