25.3 Adding the Observable Object

The first step after creating the new project is to add a data class implementing the ObservableObject protocol. Within Xcode, select the File -> New -> File… menu option and, in the resulting template dialog, select the Swift File option. Click the Next button and name the file TimerData before clicking the Create button.

With the TimerData.swift file loaded into the code editor, implement the TimerData class as follows:

import Foundation

import Combine

 

class TimerData : ObservableObject {

    

    @Published var timeCount = 0

    var timer : Timer?

    

    init() {

        timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerDidFire), userInfo: nil, repeats: true)

    }

    ...