ScClientNative

A lightweight, native iOS/macOS client written in Swift for connecting to SocketCluster servers, with no third-party dependencies.

• socketcluster.io
• socketcluster-client-swift

Overview

This version of the SocketCluster client library is designed to minimize dependencies, replacing Starscream with URLSessionWebSocketTask and removing HandyJSON entirely. It supports the essential functionality of the original library, such as:

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

Client supports following platforms

• iOS >= 15.0
• macOS >= 12.0

Installation and Use

Swift Package Manager

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

dependencies: [
   // other dependencies 
   .package(url: "https://github.com/sookim-1/socketcluster-client-swift-native.git", from: "1.0.10")
]

• To use the library add this to target dependencies

targets: [
   .target(
       name: "your_target",
       dependencies: [
   	"ScClientNative"
       ])
]

Description

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

//Create a client instance
var client = ScClient(url: "ws://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

import Foundation
import ScClientNative

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)
}

client.setBasicListener(onConnect: onConnect, onConnectError: nil, onDisconnect: onDisconnect)

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()

• For reconnecting to server:

If you are reconnecting, use the function below. Because URLWebSocketSessionTask needs to be re-created if it is reconnected.

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

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 Ping

• To send ping

client.sendPing()

• To send EmptyEvent

client.sendEmptyDataEvent()
client.sendEmptyStringEvent()

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)
}
})

Protocols

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

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