ios - Running one function after another completes

Question

I am trying to run loadViews() after the pullData() completes and I am wondering what the best way of doing this is? I would like to set a 10 sec timeout on it as well so I can display a network error if possible. From what I have read, GCD looks like it is the way to accomplish this but I am confused on the implementation of it. Thanks for any help you can give!

//1
pullData()
//2
loadViews()

Answer 1

What you need is a completion handler with a completion block.

Its really simple to create one:

func firstTask(completion: (success: Bool) -> Void) {
    // Do something

    // Call completion, when finished, success or faliure
    completion(success: true)
}

And use your completion block like this:

firstTask { (success) -> Void in
    if success {
       // do second task if success
       secondTask()
    }
}