Create segue objects programmatically - swift

Question

I created a single view app with 2 view controllers. In the first view controller, I have a label and 2 buttons that were programmatically created. I have 2 segues from these buttons to the second view controller. I wish that each button carries different information to the second view controller. From creating these buttons and segues programmatically, I haven’t been able to assign the identifier to the segues. So, I can’t use performSegue(withIdentifier: sender:).
How can I do this?
First ViewController:
import UIKit
class ViewController: UIViewController {
var myLabel: UILabel!
var leftButton: UIButton!
var rightButton: UIButton!
// bellow are the 2 variable which I’d like to transport into the second ViewController
var leftButtonText = "I'm the left button."
var rightButtonText = "I'm the right button."
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let homeNavBar = UINavigationBar()
homeNavBar.frame = CGRect(x: 0, y: 0, width: 320, height: 45)
homeNavBar.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(homeNavBar)
let homeNavItem = UINavigationItem(title: "Home")
homeNavBar.setItems([homeNavItem], animated: false)
myLabel = UILabel()
myLabel.frame = CGRect(x: 165, y: 150, width: 200, height: 42)
myLabel.text = "Press one of the button bellow!"
self.view.addSubview(myLabel)
leftButton = UIButton(type: .custom)
leftButton.frame = CGRect(x: 80, y: 300, width: 70, height: 70)
leftButton.backgroundColor = UIColor.cyan
leftButton.setTitleColor(UIColor.black, for: .normal)
leftButton.setTitle("Left Button", for: .normal)
leftButton.layer.cornerRadius = 20
leftButton.layer.borderWidth = 1
leftButton.layer.masksToBounds = true
leftButton.addTarget(self, action: #selector(ViewController.leftButtonAction(_:)), for: .touchUpInside)
self.view.addSubview(leftButton)
rightButton = UIButton(type: .custom)
rightButton.frame = CGRect(x: 240, y: 300, width: 70, height: 70)
rightButton.backgroundColor = UIColor.cyan
rightButton.setTitleColor(UIColor.black, for: .normal)
rightButton.setTitle("Right button", for: .normal)
rightButton.layer.cornerRadius = 20
rightButton.layer.borderWidth = 1
rightButton.layer.masksToBounds = true
rightButton.addTarget(self, action: #selector(ViewController.rightButtonAction(_:)), for: .touchUpInside)
self.view.addSubview(rightButton)
let margins = self.view.layoutMarginsGuide
homeNavBar.leadingAnchor.constraint(equalTo: margins.leadingAnchor).isActive = true
homeNavBar.topAnchor.constraint(equalTo: margins.topAnchor).isActive = true
homeNavBar.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true
myLabel.topAnchor.constraint(equalTo: homeNavBar.bottomAnchor).isActive = true
leftButton.leadingAnchor.constraint(equalTo: margins.leadingAnchor).isActive = true
leftButton.topAnchor.constraint(equalTo: myLabel.bottomAnchor).isActive = true
rightButton.topAnchor.constraint(equalTo: myLabel.bottomAnchor).isActive = true
rightButton.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true
}
#objc func leftButtonAction (_ sender: UIButton) {
let segueSecondViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "idSecond")
self.show(segueSecondViewController, sender: nil)
print("I'm activated by the left button.")
}
#objc func rightButtonAction (_ sender: UIButton) {
let segueSecondViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "idSecond")
self.show(segueSecondViewController, sender: nil)
print("I'm activated by the right button.")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Second ViewController:
import UIKit
class SecondViewController: UIViewController {
var mySecondLabel: UILabel!
var mySecondLabelText = "I'm the second page."
var closeButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let secondNavBar = UINavigationBar()
secondNavBar.frame.size = CGSize(width: 320, height: 45)
secondNavBar.translatesAutoresizingMaskIntoConstraints = false
let secondNavItem = UINavigationItem(title: "Second page")
secondNavBar.setItems([secondNavItem], animated: false)
self.view.addSubview(secondNavBar)
mySecondLabel = UILabel()
mySecondLabel.frame = CGRect(x: 165, y: 200, width: 200, height: 42)
mySecondLabel.backgroundColor = UIColor.yellow
mySecondLabel.textColor = UIColor.black
mySecondLabel.text = "\(mySecondLabelText)"
mySecondLabel.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(mySecondLabel)
closeButton = UIButton(type: .custom)
closeButton.frame = CGRect(x: 10, y: 50, width: 50, height: 50)
closeButton.backgroundColor = UIColor.red
closeButton.setTitleColor(UIColor.black, for: .normal)
closeButton.setTitle("Close", for: .normal)
closeButton.layer.cornerRadius = 30
closeButton.layer.borderWidth = 1
closeButton.layer.masksToBounds = true
closeButton.addTarget(self, action: #selector(SecondViewController.closeButtonAction(_:)), for: .touchUpInside)
self.view.addSubview(closeButton)
let margins = self.view.layoutMarginsGuide
secondNavBar.leadingAnchor.constraint(equalTo: margins.leadingAnchor).isActive = true
secondNavBar.topAnchor.constraint(equalTo: margins.topAnchor).isActive = true
secondNavBar.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true
closeButton.leadingAnchor.constraint(equalTo: margins.leadingAnchor).isActive = true
closeButton.topAnchor.constraint(equalTo: secondNavBar.bottomAnchor).isActive = true
mySecondLabel.leadingAnchor.constraint(equalTo: margins.leadingAnchor).isActive = true
mySecondLabel.topAnchor.constraint(equalTo: closeButton.bottomAnchor).isActive = true
mySecondLabel.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true
}
#objc func closeButtonAction (_ sender: UIButton) {
self.dismiss(animated: true, completion: nil)
print("Second page closed.")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}

Answer 1

You can do it by giving your View Controller an Identifier. This isn't a segue, but it will Instantiate your target VC:
let vc = UIStoryboard(name:"Main", bundle:nil).instantiateViewControllerWithIdentifier("identifier") as! SecondViewController
self.navigationController?.pushViewController(vc, animated:true)
You can set the VC Identifier on the Identity Inspector tab on the StoryBoard.
I just read in the documentation that you can't call the performSegue method if you don't have a segue with an identifier in the Storyboard, so WRT your requirement, you can't do it programmatically.
identifier The string that identifies the triggered segue. In
Interface Builder, you specify the segue’s identifier string in the
attributes inspector.