iOS Swift Programmatically Trigger button from previous ViewController - ios

Question

When BackgroundClicked is triggered go back to the previous viewcontroller and programatically click on a button on the previous viewcontroller on the load. But only if BackgroundClicked was clicked from the child view controller
for example
//this button is on child controller
#IBAction func BackgroundClicked(sender: AnyObject)
{
self.navigationController?.popToRootViewControllerAnimated(true)
// when im on the root controller click button abc
// button abc resides on the root controller
}
I only want button abc clicked on the load of the root controller only if BackgroundClicked was clicked. I'm not sure how to go about this or if it's even possible

Answer 1

You can send a notification when button is pressed into your ChildViewController like show in below:
Add this code in your ChildViewController when you press a button:
#IBAction func BackgroundClicked(sender: AnyObject)
{
NSNotificationCenter.defaultCenter().postNotificationName("refresh", object: nil)
self.navigationController?.popToRootViewControllerAnimated(true)
}
In your ParentViewController add this code into your viewDidLoad method:
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "refreshList:", name:"refresh", object: nil)
}
and here is your helper function:
func refreshList(notification: NSNotification){
println("parent method is called")
}
Now when ever you press back button from your ChildViewController refreshList method will call from your ParentViewController.
Check THIS sample project for more Info.
Hope this will help.

Answer 2

So that will go back to the root view controller, but what you want to do is you want to create a function in the previous view controller. In the code in the viewController that you are going back to run the name of the function in the viewDidLoad() method. Also whenever you click the back button you want to change the value of a variable because you don't want to run the function every time int he viewDidLoad(). This is what the code to the previous view controller should look like:
var decideInt: Int = 0
override func viewDidLoad() {
super.viewDidLoad()
if decideInt == 0 {
// Do Nothing
} else if decideInt == 1 {
functionYouWantToRun()
decideInt = 0
}
}
func functionYouWantToRun() {
//Write the code to the function you want to run
}
Here is the code that you need to write to go back:
//this button is on child controller
#IBAction func BackgroundClicked(sender: AnyObject)
{
self.navigationController?.popToRootViewControllerAnimated(true)
var goToView: DestinationViewControllerName = DestinationViewControllerName()
goToView.decideInt = 1
}