CODEWITHSUNDEEP
swiftmacoscocoaviewcontroller
O.Naeem
O.Naeem

Reputation: 45

How to pass data to a previous ViewController in Swift (Cocoa Application)

Passing data to the next viewController is simple and straightforward, and can be done using prepareSegue method. However, I can't understand how to pass data to a previous viewController in Swift(Cocoa Application)

I have a textfield in viewControllerB and when you type something in it and press a button, I want to pass it to a label in viewControllerA and instead of opening the viewControllerA in a new window, I just want the viewController B to be dismissed and the passed data to be visible on the viewControllerA.

That's all there is to it. I have been stuck on it for the past 48 hours. Any help on this will be appreciated.

Thanks!

Upvotes: 1

Views: 667

Answers (1)

Sealos
Sealos

Reputation: 562

You do this using delegates. Example:

protocol NextProtocol: class {
    func sendBack(value: Int)
}

class Previous: NextProtocol {
    func sendBack(value: Int) {
        print("I have received \(value)")
    }

    func prepareSegue(...) {
        // get next instance
        var next: Next
        next.delegate = self
    }
}

class Next {
   weak var delegate: NextProtocol?

   func someMethod() {
       delegate?.sendBack(5)
   }  
}

Upvotes: 2

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