Swift 3 Singleton Manager套接字连接

Question

Is this the proper way to manage socket connections in Swift 3 using Singleton?

Where do I start a socket connection such that I do not have to reconnect every time in the Viewcontroller lifecycle? The Viewcontroller is constantly sending data to my server; my app is the client and its collecting data; its getting the data from movement within the app and sending direction, power, etc..

I have searched and searched but I cannot find a concrete example; I only find socket libraries but not any examples on how to use it with UIViewcontroller; also, most examples online are using websockets, I am not

Any suggestions?

I am hoping this will work:

        manager.messageReceived(message: "Testing...")

but my fear is that inside the UIViewcontroller class, it will automatically start a connection again; also, I am not sure at which point I should check if connection is lost and where to connect again; as I am never closing the socket

Thanks

Singleton Class:

import Darwin
import Foundation

class ChatManager {

    // Add property for socket

    private var control_socket: Int32
    private var address = "000.000.0.000"
    private var port = "0000"

    class var sharedInstance: ChatManager {
        struct Singleton { static let instance = ChatManager() }
        return Singleton.instance
    }

    init() {
        // Create the socket
        self.control_socket = connectToServer(atAddress: self.address, atPort: self.port)

    }

    func sendMessage(message: String) {
        // Push the message onto the socket
        _ = write(self.control_socket, message, message.characters.count)
    }

    // Delegate methods

    func messageReceived(message: String) {

        // Emit the message using NSNotificationCenter
    }
}

UIViewcontroller:

import Darwin
import Foundation
import UIKit
import Dispatch

class ViewController: UIViewController {

    @IBOutlet private weak var joystickMove: Joystick!
    @IBOutlet private weak var joystickRotate: Joystick!

    private var contour = Contours()
    private var contour_index: Int = 0

    private let manager = ChatManager.sharedInstance

    override func viewDidLoad() {
        super.viewDidLoad()
        createJoystick()
        createContours()
        createButton()
    }

    private func createJoystick() {

        var joystick = Joystick()

        let n: CGFloat = 100.0
        let x: CGFloat = (UIScreen.main.bounds.width/2) - (n/2.0)
        let y: CGFloat = UIScreen.main.bounds.height - (UIScreen.main.bounds.height/4.0)

        joystick.frame = CGRect(x: x, y: y, width: n, height: n)
        joystick.backgroundColor =  UIColor.clear

        joystick.substrateColor = UIColor.lightGray
        joystick.substrateBorderColor = UIColor.gray
        joystick.substrateBorderWidth = 1.0
        joystick.stickSize = CGSize(width: 50.0, height: 50.0)
        joystick.stickColor = UIColor.darkGray
        joystick.stickBorderColor = UIColor.black
        joystick.stickBorderWidth = 2.0
        joystick.fade = 0.5

        var packet = ""

        joystick.trackingHandler = { (data) -> () in

            let power = sqrt(pow(Double(data.velocity.x), 2.0) + pow(Double(data.velocity.y), 2.0))
            let theta = atan2(Double(-data.velocity.y), Double(data.velocity.x))
            let degrees = theta * (180.0 / M_PI)

            if degrees >= 55 && degrees <= 125 { // move forward
                packet = "\(1) \(1) \(power) \(power)"
            } else if degrees >= -125 && degrees <= -55 { // move backewards
                packet = "\(-1) \(-1) \(power) \(power)"
            } else if degrees >= -55 && degrees <= 55 { // turn right
                packet = "\(1) \(-1) \(power) \(power)"
            } else if (degrees >= 125 && degrees <= 180) && (degrees >= -180 && degrees <= -125) { // turn left
                packet = "\(-1) \(1) \(power) \(power)"
            }

        }

        manager.messageReceived(message: "Testing...")

        view.addSubview(joystick)
    }
}

Answer 1

Since it is a singleton, have you considered initializing the Socket Manager in AppDelegate's application function? Then it will exist for the lifetime of the app.