Question: How to ensure only a single tap is responded to on a UIButton?

[nasht]

Apologies if this is obvious - I'm still relatively new to ReactiveSwift...

Right now I have some code like this

myButton.reactive
            .controlEvents(.touchUpInside)
            .observeValues  { 
 <some async operation here>
}

If I tap the button multiple times, the code above will reasonably run for each tap.

What is the best (reactive) way to disregard multiple taps, and respond to a single tap only? I can solve this using semaphores, and setting the button disabled / enabled, but surely there is a more elegant way to do it?

I've tried using debounce(X) but that lets me keep tapping the button for a while, and can still sometimes yield multiple taps.

Also to be clear, I don't want the signal to run only once, so skipDuplicates() doesn't seem quite right either...

Many thanks!

[sharplet]

Is your goal to prevent the async code from running multiple times in parallel? The way I'd recommend doing that is to wrap your async work in a SignalProducer, and then use an Action to bind it to your button.

First define your async work in a function that returns a new SignalProducer:

func work() -> SignalProducer<Foo, MyError> {
  // ...
}

Then wrap it in an action:

let workAction = Action(execute: work) // Action<(), Foo, MyError>

Now you can bind it to your button:

func viewDidLoad() {
  super.viewDidLoad()

  workButton.reactive.pressed = CocoaAction(workAction)
}

Whenever the button is tapped, the action will be executed. The button's isEnabled property is also bound to the action's isEnabled property, meaning that it is disabled while the work is executing. You can read a bit more about Action here: https://github.com/ReactiveCocoa/ReactiveSwift/blob/master/Documentation/ReactivePrimitives.md#action-a-serialized-worker-with-a-preset-action.

There are other ways to compose signals and signal producers, but for the purposes of binding work to a button, Action is a really useful tool. (For example, it allows you to display/handle errors separately via its errors signal.)

[RuiAAPeres]

Hello. 👋 Thanks for opening this issue. Due to inactivity, we will soft close the issue. If you feel that it should remain open, please let us know. 😄