socketcluster-client-swift

Native iOS/macOS client written in swift

Overview

This client provides following functionality

• Easy to setup and use
• Support for emitting and listening to remote events
• Pub/sub
• Authentication (JWT)

Client supports following platforms

• iOS >= 8.0
• macOS>= 10.10
• watchOS >= 2.0
• tvOS >= 9.0

Installation and Use

CocoaPods

pod 'ScClient'

Swift Package Manager

• To install add this to depedencies section of Package.swift

    dependencies: [
        // other dependencies 
       .package(url: "https://github.com/sacOO7/ScClient", from: "2.0.1")
   ]

• To use the library add this to target dependencies

   targets: [
       .target(
           name: "tool",
           dependencies: [
               "ScClient"
           ])
   ]

Description

Create instance of scclient by passing url of socketcluster-server end-point

    //Create a client instance
    var client = ScClient(url: "http://localhost:8000/socketcluster/")
    

Important Note : Default url to socketcluster end-point is always ws://somedomainname.com/socketcluster/.

Registering basic listeners

• Different closure functions are given as an argument to register listeners
• Example : main.swift

        import Foundation
        import ScClient
        
        var client = ScClient(url: "http://localhost:8000/socketcluster/")

        var onConnect = {
            (client :ScClient) in
            print("Connnected to server")
        }

        var onDisconnect = {
            (client :ScClient, error : Error?) in
                print("Disconnected from server due to ", error?.localizedDescription)
        }

        var onAuthentication = {
            (client :ScClient, isAuthenticated : Bool?) in
            print("Authenticated is ", isAuthenticated)
            startCode(client : client)
        }

        var onSetAuthentication = {
            (client : ScClient, token : String?) in
            print("Token is ", token)
        }
        client.setBasicListener(onConnect: onConnect, onConnectError: nil, onDisconnect: onDisconnect)
        client.setAuthenticationListener(onSetAuthentication: onSetAuthentication, onAuthentication: onAuthentication)
        
        client.connect()
        
        while(true) {
            RunLoop.current.run(until: Date())
            usleep(10)
        }
        
        func startCode(client scclient.Client) {
            // start writing your code from here
            // All emit, receive and publish events
        }
        

Connecting to server

• For connecting to server:

    //This will send websocket handshake request to socketcluster-server
    client.connect()

Getting connection status

    //This will send websocket handshake request to socketcluster-server
    var status = client.isConnected()

Emitting and listening to events

Event emitter

• eventname is name of event and message can be String, boolean, Int or Object

    client.emit(eventName: eventname, data: message as AnyObject)
    
  //client.emit(eventName: "chat", data: "This is my sample message" as AnyObject)
  

• To send event with acknowledgement

    client.emitAck(eventName: "chat", data: "This is my sample message" as AnyObject, ack : {
            (eventName : String, error : AnyObject? , data : AnyObject?) in
            print("Got data for eventName ", eventName, " error is ", error, " data is ", data)  
    })
    

Event Listener

• For listening to events :

The object received can be String, Boolean, Int or Object

    // Receiver code without sending acknowledgement back
    client.on(eventName: "yell", ack: {
            (eventName : String, data : AnyObject?) in
            print("Got data for eventName ", eventName, " data is ", data)
    })
    

• To send acknowledgement back to server

    // Receiver code with ack
    client.onAck(eventName: "yell", ack: {
            (eventName : String, data : AnyObject?, ack : (AnyObject?, AnyObject?) -> Void) in
            print("Got data for eventName ", eventName, " data is ", data)
            ack("This is error " as AnyObject, "This is data " as AnyObject)
    })
        

Implementing Pub-Sub via channels

Creating channel

• For creating and subscribing to channels:

    // without acknowledgement
    client.subscribe(channelName: "yell")
    
    //with acknowledgement
    client.subscribeAck(channelName: "yell", ack : {
        (channelName : String, error : AnyObject?, data : AnyObject?) in
        if (error is NSNull) {
            print("Successfully subscribed to channel ", channelName)
        } else {
            print("Got error while subscribing ", error)
        }
    })

Publishing event on channel

• For publishing event :

    // without acknowledgement
    client.publish(channelName: "yell", data: "I am sending data to yell" as AnyObject)


    // with acknowledgement
    client.publishAck(channelName: "yell", data: "I am sending data to yell" as AnyObject, ack : {
        (channelName : String, error : AnyObject?, data : AnyObject?) in
        if (error is NSNull) {
             print("Successfully published to channel ", channelName)
        }else {
             print("Got error while publishing ", error)
        }
    })

Listening to channel

• For listening to channel event :

        client.onChannel(channelName: "yell", ack: {
            (channelName : String , data : AnyObject?) in
            print ("Got data for channel", channelName, " object data is ", data)
    })

Un-subscribing to channel

    // without acknowledgement
    client.unsubscribe(channelName: "yell")
    
    //with acknowledgement
    client.unsubscribeAck(channelName: "yell", ack : {
        (channelName : String, error : AnyObject?, data : AnyObject?) in
        if (error is NSNull) {
            print("Successfully unsubscribed to channel ", channelName)
        } else {
            print("Got error while unsubscribing ", error)
        }
    })

Disable SSL Certificate Verification

    var client = ScClient(url: "http://localhost:8000/socketcluster/")
        client.disableSSLVerification(true)

Custom Queue

A custom queue can be specified when delegate methods are called. By default DispatchQueue.main is used, thus making all delegate methods calls run on the main thread. It is important to note that all WebSocket processing is done on a background thread, only the delegate method calls are changed when modifying the queue. The actual processing is always on a background thread and will not pause your app.

    var client = ScClient(url: "http://localhost:8000/socketcluster/")
    //create a custom queue
    client.setBackgroundQueue(queueName : "com.example.chatapp")

Custom Headers

You can also override the default websocket headers with your own custom ones like so:

    var request = URLRequest(url: URL(string: "http://localhost:8000/socketcluster/")!)
    request.timeoutInterval = 5
    request.setValue("someother protocols", forHTTPHeaderField: "Sec-WebSocket-Protocol")
    request.setValue("14", forHTTPHeaderField: "Sec-WebSocket-Version")
    request.setValue("Everything is Awesome!", forHTTPHeaderField: "My-Awesome-Header")
    var client = ScClient(URLRequest: request)

Custom HTTP Method

Your server may use a different HTTP method when connecting to the websocket:

    var request = URLRequest(url: URL(string: "http://localhost:8000/socketcluster/")!)
    request.httpMethod = "POST"
    request.timeoutInterval = 5
    var client = ScClient(URLRequest: request)

Protocols

If you need to specify a protocol, simple add it to the init:

    //chat and superchat are the example protocols here
    var request = URLRequest(url: URL(string: "http://localhost:8000/socketcluster/")!)
    var client = ScClient(URLRequest: request, protocols: ["chat","superchat"])