Reactive Swift consume live data from API - need basic example

Question

I’m new to RxSwift and I’m looking for a basic example of how to print in console live data streaming from an backend. I have a backend which is streaming some dummy data every 1 second, I can see it with a curl request and I want to be able to observe and subscribe and print it out in console automatically, please help!

Answer 1

I assume you are opening a socket connection to your server in order to receive live data. You can use RxWebSocket to handle this data flow. There are examples in the documentation/readme for the API.

Answer 2

https://github.com/daltoniam/Starscream/tree/master/examples/SimpleTest/SimpleTest

import UIKit
import Starscream

class ViewController: UIViewController, WebSocketDelegate {
var socket: WebSocket!

@IBOutlet weak var label: UILabel!
@IBOutlet weak var textField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()
    var request = URLRequest(url: URL(string: "wss://echo.websocket.org")!)
    request.timeoutInterval = 5
    socket = WebSocket(request: request)
    socket.delegate = self
    socket.connect()
}

// MARK: Websocket Delegate Methods.

func websocketDidConnect(socket: WebSocketClient) {
    print("websocket is connected")
}

func websocketDidDisconnect(socket: WebSocketClient, error: Error?) {
    if let e = error as? WSError {
        print("websocket is disconnected: \(e.message)")
    } else if let e = error {
        print("websocket is disconnected: \(e.localizedDescription)")
    } else {
        print("websocket disconnected")
    }
}

func websocketDidReceiveMessage(socket: WebSocketClient, text: String) {
    self.label.text = text
    print("Received text: \(text)")
}

func websocketDidReceiveData(socket: WebSocketClient, data: Data) {
    print("Received data: \(data.count)")
}

// MARK: Write Text Action

@IBAction func send(_ sender: UIButton) {
    socket.write(string: "Hello \(textField.text!)")
}

// MARK: Disconnect Action

@IBAction func disconnect(_ sender: UIBarButtonItem) {
    if socket.isConnected {
        sender.title = "Connect"
        socket.disconnect()
    } else {
        sender.title = "Disconnect"
        socket.connect()
    }
}

}

extension URL {
    init(staticString string: StaticString) {
        guard let url = URL(string: "\(string)") else {
            preconditionFailure("Invalid static URL string: \(string)")
        }

        self = url
    }
}