ReactiveCocoa 4 - Delaying and filtering signal events

Question

I am implementing a search textfield using ReactiveCocoa 4, and want to only hit the search API after no text has been inputted for X amount of time. I have done this previously by canceling previously scheduled and firing off a "executeSearch" selector in the textDidChange delegate method. This ensures that every time I type, any previously scheduled "executeSearch" selector is canceled, and a new one is scheduled to fire in X seconds.

I now want to do this same behavior, but from a signal producer bound to my input text. My current implementation is close, but not the same. This behavior merely throttles the text input event to only fire every 0.5 seconds, instead of canceling the previous event.

searchTextInput.producer.delay(0.3, onScheduler: RACScheduler.currentScheduler())
                        .throttle(0.5, onScheduler: RACScheduler.currentScheduler())
                        .producer.startWithNext({ [unowned self] searchText in
                           self.executeSearch(searchText)
                        })

I'm having a hard time sifting through the ReactiveCocoa 4 documentation to know which signal functions I should be using! Thank you!

score 3 · Answer 1 · answered Aug 26 '16 at 02:41

You need use DateSchedulerType. For example:

textField.rac_textSignal()
            .toSignalProducer()
            .map { $0 as! String }
            .flatMapError { _ in SignalProducer<String, NoError>.empty }
            .throttle(2.0, onScheduler: QueueScheduler.mainQueueScheduler)
            .filter { $0.isEmpty }
            .startWithNext { text in
                print("t: \(text)")
        }

Also you can write your executeSearch as SignalProducer and use flatMap(.Latest) for create signal-chains.

And don't forget using mainQueueSheduler for get result to UI

ReactiveCocoa 4 - Delaying and filtering signal events

1 Answers1