Socket.IO / Objective C Library

Description : 

Link : https://github.com/pkyeck/socket.IO-objc

Interface to communicate between Objective C and Socket.IO with the help of websockets or Long-Polling. Originally based on fpotter's socketio-cocoa it uses other libraries/classes like

• SocketRocket Look here for further instructions how to use/install SocketRocket.

Requirements

As of version 0.4, this library requires at least OS X 10.7 or iOS 5.0. Because of this, we were able to remove the external JSON frameworks in v0.5 and only rely on iOS' own NSJSONSerialization.

Usage

The easiest way to connect to your Socket.IO / node.js server is

SocketIO *socketIO = [[SocketIO alloc] initWithDelegate:self];
[socketIO connectToHost:@"localhost" onPort:3000];

If required, additional parameters can be included in the handshake by adding an NSDictionary to the withParamsoption:

[socketIO connectToHost:@"localhost"
                 onPort:3000
             withParams:@{@"auth_token":@"1234"}];

A namespace can also be defined in the connection details:

[socketIO connectToHost:@"localhost" onPort:3000 withParams:nil withNamespace:@"/users"];

There are different methods to send data to the server

- (void) sendMessage:(NSString *)data;
- (void) sendMessage:(NSString *)data withAcknowledge:(SocketIOCallback)function;
- (void) sendJSON:(NSDictionary *)data;
- (void) sendJSON:(NSDictionary *)data withAcknowledge:(SocketIOCallback)function;
- (void) sendEvent:(NSString *)eventName withData:(NSDictionary *)data;
- (void) sendEvent:(NSString *)eventName withData:(NSDictionary *)data andAcknowledge:(SocketIOCallback)function;

So you could send a normal Message like this

[socketIO sendMessage:@"hello world"];

or an Event (including some data) like this

NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[dict setObject:@"test1" forKey:@"key1"];
[dict setObject:@"test2" forKey:@"key2"];

[socketIO sendEvent:@"welcome" withData:dict];

If you want the server to acknowledge your Message/Event you would also pass a SocketIOCallback block

SocketIOCallback cb = ^(id argsData) {
    NSDictionary *response = argsData;
    // do something with response
};
[socketIO sendEvent:@"welcomeAck" withData:dict andAcknowledge:cb];

All delegate methods are optional - you could implement the following

- (void) socketIODidConnect:(SocketIO *)socket;
- (void) socketIODidDisconnect:(SocketIO *)socket disconnectedWithError:(NSError *)error;
- (void) socketIO:(SocketIO *)socket didReceiveMessage:(SocketIOPacket *)packet;
- (void) socketIO:(SocketIO *)socket didReceiveJSON:(SocketIOPacket *)packet;
- (void) socketIO:(SocketIO *)socket didReceiveEvent:(SocketIOPacket *)packet;
- (void) socketIO:(SocketIO *)socket didSendMessage:(SocketIOPacket *)packet;
- (void) socketIO:(SocketIO *)socket onError:(NSError *)error;

To process an incoming message or event just

// message delegate
- (void) socketIO:(SocketIO *)socket didReceiveMessage:(SocketIOPacket *)packet
{
    NSLog(@"didReceiveMessage >>> data: %@", packet.data);
}

// event delegate
- (void) socketIO:(SocketIO *)socket didReceiveEvent:(SocketIOPacket *)packet
{
    NSLog(@"didReceiveEvent >>> data: %@", packet.data);
}

Usage with OS X

Running the socket.io-objc library with OS X requires some minor changes:

• you have to use the SocketRocket.framework for OSX instead of just the submodule
  see: SocketRocket's Installing OS X
  (best way I got this to work was as a subproject and I didn't have to add the "copy file" stuff)
• when using the osx-framework, you have to fix the import-statement in SocketIOTransportWebsocket.h

// replace
#import SRWebSocket.h

// with
#import <SocketRocket/SRWebSocket.h>