CODEWITHSUNDEEP
iosswiftuinavigationcontroller
Arinjay
Arinjay

Reputation: 69

Navigate to same screen but from two different viewcontroller

So I have 3 VC

ViewController1,ViewController2,ViewController3

Now I have a button in ViewController2 and ViewController3, which on tapping navigates to ViewController1 there is a slight change in the UI of when navigating from vc2 and when from vc3.

So I want to know the best practice of handling this problem ie. how would I know from which vc have I reached to VC1.?

Upvotes: 0

Views: 96

Answers (3)

dahiya_boy
dahiya_boy

Reputation: 9503

You can either use a flag or enum. I suggest for enum bcz sometimes in future you might push from multiple controllers to VC1. Its always handy to use a enum.

  1. With flag 
class ViewController1: UIViewController {
    // default value is false bcz if you forgot to assign this value then atleast your app won't crash.
    var isFromVC2 : Bool = false
        :
        :
}

  • Use -> In your VC1 file

    if isFromVC2 {
    // Do code for VC2
}
else {
    // Do code for VC3
}
  1. With Enum
enum ComingFrom {
    case VC3
    case VC2
}

class ViewController: UIViewController {
    // default value VC2
    var whichController : ComingFrom = .VC2
      :
      :
}

  • Use 

    switch whichController {
    case .VC2:
        // for vc2 Code
    case .VC3:
        // for VC3 Code
    default:
        // If you forget to assign `whichController` or there will be new condition in future
}

Edit : How to assign whichController

let vc = self.storyboard?.instantiateViewController(withIdentifier: "ViewController1") as! ViewController1
vc.whichController = .VC2
self.navigationController?.pushViewController(vc, animated: true)
  • For More Clearity

enter image description here

Upvotes: 2

Abhishek Jadhav
Abhishek Jadhav

Reputation: 706

Add unique Bool variable so you can understand where to come to this controller. Make flag false in viewWillAppear because every time it should be updated its a simplest way that you can achieve.

class ViewController1: UIViewController {
      var isFromVC2 = false
      var isFromVC3 = false

     override func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(true)
         isFromVC2 = false
         isFromVC3 = false
     }

}


class ViewController2: UIViewController {


 //You can call this function from where you want otherwise you can make it global.
    func navigateToVC1() {
        let viewController1 = self.storyboard?.instantiateViewController(withIdentifier: "ViewController1") as! ViewController1
        viewController1.isFromVC2 = true
        self.navigationController?.pushViewController(viewController1, animated: true)
    }


}

class ViewController3: UIViewController {

    func navigateToVC1() {
        let viewController1 = self.storyboard?.instantiateViewController(withIdentifier: "ViewController1") as! ViewController1
        viewController1.isFromVC3 = true
        self.navigationController?.pushViewController(viewController1, animated: true)
    }

}

Upvotes: 1

Abdul Hoque Nuri
Abdul Hoque Nuri

Reputation: 1097

In your VC1, create a variable as vcNames.

class VC1: UIViewController {
        var vcNames = ""
 override func viewDidLoad() {
        super.viewDidLoad()
        //Check your vc's with vcNames.
   }
}

Now while pushing to vc1 from VC2 or VC3, Just pass your current vc name with created variable.

 let tempVC1 = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "VC1") as? VC1
 tempVC1?.vcNames =  "vc2" //Assign your vc name here
 self.navigationController?.pushViewController(tempVC1!, animated: true)

Upvotes: 1

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