Alex Cauthen Alex Cauthen - 1 year ago 56
Swift Question

Swift: Keep segue from executing if condition not met

Currently I'm working on two different ViewControllers in my application, we can call them VC1 and VC2. VC1 displays a registration form, with a question in each row of a UITableView, and has an edit button. The edit button is as a segue from VC1 and VC2. VC2 displays an interface that will allow the user to edit the question. I want to write the application so that you cannot segue from VC1 to VC2 unless you have selected a question(row) to edit. Right now I have some of it set up, but it's possible that I have it backwards.

In VC1:

// this method isn't called until VC2 segues back to VC1... so I don't know how
// to make sure that a selection has been made before pressing the button
@IBAction func editQuestion(segue:UIStoryboardSegue) {
if let editQuestion = segue.sourceViewController as? VC2 {

}
}


In VC2:

override func shouldPerformSegueWithIdentifier(identifier: String, sender: AnyObject!) -> Bool {

// check to make sure that user has completed all fields of question
// if they haven't completed all fields, return false (do not segue)
// else segue to VC1
}

Answer Source

Implement in VC1:

override func shouldPerformSegueWithIdentifier(identifier: String, sender: AnyObject?) -> Bool {
        if identifier == <your storyboard segue identifier> {

        }
    } 

Give your storyboard segue an identifier, and then you can do the check in VC1, and return false if you do not want the segue to happen.

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