CoreWebSocket is an C language, Core Foundation based library for iOS and Mac OSX. It can be used from Objective-C.
WebSocket enables low latency, bi-directional, full-duplex communication channel over TCP with web browser. It works with all modern web browsers including Safari, Chrome, Firefox and Opera. It works with iOS Safari as well.
To use the library in your git project:
git submodule add git://github.com/mirek/CoreWebSocket.git CoreWebSocket
Link your target with:
CFNetwork.framework- on iOSlibcrypto.dylib,CoreServices.framework- on Mac OSX
#include "CoreWebSocket/CoreWebSocket.h"
// Somewhere in init
CFAllocatorRef allocator = NULL;
WebSocketRef webSocket = CoreWebSocketCreate(allocator, CFSTR("localhost"), 60001);
// Send data to all connected clients
WebSocketWriteWithString(webSocket, CFSTR("foo, bar"));
// To receive data from connected clients, declare the callback of type:
// typedef void (*WebSocketDidClientReadCallback) (WebSocketRef webSocket, WebSocketClientRef client, CFStringRef value);
void MyWebSocketDidClientReadCallback(WebSocketRef webSocket, WebSocketClientRef client, CFStringRef value) {
printf("my read callback, the client sent:\n");
CFShow(value);
}
// ...and set the callback:
WebSocketSetClientReadCallback(webSocket, MyWebSocketDidClientReadCallback);
// Somewhere in dealloc
WebSocketRelease(webSocket);
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=utf-8">
<script type="text/javascript" charset="utf-8">
// WebSocket
var ws = null;
// When the page is loaded...
window.addEventListener('load', function(e) {
// Check if the browser supports WebSockets...
if ("WebSocket" in window) {
// ...it does, let's connect to localhost default port.
// Make sure Quartz Composer composition is running with
// the WebSocket Patch set to port 60001.
ws = new WebSocket('ws://localhost:60001');
// Invoked when there was an error with the connection.
ws.onerror = function(e) {
console.log('error', e);
}
// Invoked when the socket has been opened successfully.
ws.onopen = function(e) {
console.log('open', e);
}
// Callback invoked when incoming messages arrive. Event `data` attribute
// holds the string passed. WebSocket in current spec supports utf8 text-based
// communication only. Binary data is base64 encoded.
ws.onmessage = function(e) {
var json = JSON.parse(e.data);
console.log('message', json);
}
// Invoked when the socket has been closed
ws.onclose = function(e) {
console.log('close', e);
}
} else {
// ...seems like the web browser doesn't support WebSockets.
alert('WebSocket not supported by your browser, use Safari, Chrome or Firefox');
}
}, false);
</script>
</head>
</html>
Unless otherwise stated, the code is released under Open Source MIT License, (c) Copyright Mirek Rusin <mirek [at] me [dot] com>
Parts of the source code (particularly Base64 encoding functions) have been copied from http://opensource.apple.com which are released under Apple Public Source License 2.0 http://www.opensource.apple.com/apsl.
Portions of the copied source code could be modified.