Introduction to Functional Reactive Programming

2016-06-01T02:25:24+07:00

Good job! Can you share about some book and experience of learning FRP. Thank you!

2016-06-01T05:47:58+07:00

Thanks. This article is not finish right now. I will share some experience and resources, helpful blogs for learning FRP within 1-2 next days.

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2016-06-03T07:27:44+07:00

Awesome, thank you very much. I’m looking forward many examples for next post.

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2016-06-20T03:33:27+07:00

Very helpful, thanks a lot. I’m starting FRP with RxSwift and MVVM. And this post helps me a lot. Thanks !

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2016-06-20T03:55:53+07:00

You are welcome :).

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2016-06-22T04:23:18+07:00

Very appreciate if you could have another blogs for RxSwift later 😉

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2016-06-23T03:36:59+07:00

Could you please give me your skype ID 🙂 Thanks

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2016-06-23T04:05:05+07:00

Skype: dangthaison.91. You can easily get it from about. 😉

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2016-07-16T14:35:31+07:00

Cho e add anh vao luon nha

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2016-07-16T20:18:44+07:00

Add zô đâu em ei?

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2016-07-24T06:31:44+07:00

để em add skype của anh luôn ,bữa máy em bị rớt mạng tưởng tin nhắn ko gửi lên đc ai ngờ lại gủi đc . 😀 Em đang nghiên cứu Functional Programing , và có đôi cái muốn thỉnh giáo anh 😀

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2017-02-15T11:42:30+07:00

Bài viết quá chất 🙂
Mình cũng có 1 dự án viết bằng Swift. Sử dụng ReactiveCocoa trong mô hình MVVM ở đây
https://github.com/swift-boilerplate/swift-boilerplate

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2017-08-31T09:03:45+07:00

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2022-02-08T16:51:57+07:00

thanks for sharing. it is really nice

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	private var lastScheduledWord: dispatch_cancelable_block_t?
	private var lastRequest: NSURLSessionTask?

	func searchRepository(keyword: String) {
	cancel_block(lastScheduledWord)

	lastRequest?.cancel()
	lastRequest = nil

	lastScheduledWord = dispatch_after_delay(0.5) {
	lastRequest = findRepository(keyword, success: { repository in
	findIssues(repository)
	}, failure: { error in
	displayError(error)
	}
	})
	}
	}

	// Fire API request then bindTo Tableview
	searchBar
	.rx_text
	.throttle(0.5, scheduler: MainScheduler.instance)
	.distinctUntilChanged()
	.filter { $0.characters.count > 0 }
	.flatMapLatest { findRepository($0) }
	.flatMapLatest { repository -> [Issue] in
	return findIssues(repository)
	}
	.filterNull()

	private var lastScheduledWord: dispatch_cancelable_block_t?
	private var lastRequest: NSURLSessionTask?
	var numberOfRetries = 3
	let NUMBER_OF_RETRIES = 3

	func searchRepository(keyword: String) {
	cancel_block(lastScheduledWord)

	lastRequest?.cancel()
	lastRequest = nil

	lastScheduledWord = dispatch_after_delay(0.5) {
	lastRequest = findRepository(keyword, success: { repository in
	findIssues(repository)
	}, failure: { error in
	if numberOfRetries++ < NUMBER_OF_RETRIES {
	searchRepository(keyword)
	} else {
	numberOfRetries = 0
	displayError(error)
	}
	})
	}
	}

	// Fire API request
	searchBar
	.rx_text
	.throttle(0.5, scheduler: MainScheduler.instance)
	.distinctUntilChanged()
	.filter { $0.characters.count > 0 }
	.flatMapLatest { findRepository($0).retry(3) }
	.flatMapLatest { repository -> [Issue] in
	return findIssues(repository)
	}
	.filterNull()

	class ImperativeShortViewController: UIViewController {
	private var timerCreator: TimerCreator

	private var panPresent = false
	private var rotatePresent = false
	private var gestureTimer: TimerType?
	private var secondsLeft = 3
	private var tickCount = 0

	init(timerCreator: TimerCreator) {
	self.timerCreator = timerCreator
	}

	func handlePan(panGesture: UIPanGestureRecognizerType) {
	if panGesture.state == .Began && self.panPresent == false {
	self.panPresent = true
	self.checkIfBothGesturesPresent()
	} else if panGesture.state == .Ended {
	self.panPresent = false
	self.stopTimerIfNeeded()
	}
	}

	func handleRotate(rotateGesture: UIRotationGestureRecognizerType) {
	if rotateGesture.state == .Began && self.rotatePresent == false {
	self.rotatePresent = true
	self.checkIfBothGesturesPresent()
	} else if rotateGesture.state == .Ended {
	self.rotatePresent = false
	self.stopTimerIfNeeded()
	}
	}

	private func checkIfBothGesturesPresent() {
	if self.rotatePresent == true && self.panPresent == true && self.gestureTimer == nil {
	self.secondsLeft = 3
	self.gestureTimer = timerCreator(interval: 1, repeats: true, onTick: { [weak self] sender in
	self?.tick(sender)
	})
	delegate?.didStart()
	}
	}

	private func stopTimerIfNeeded() {
	if let gestureTimer = gestureTimer {
	gestureTimer.invalidate()
	self.gestureTimer = nil
	self.tickCount = 0
	delegate?.didComplete()
	}
	}

	private func tick(timer: TimerType) {
	if self.secondsLeft <= 0 {
	self.stopTimerIfNeeded()
	return
	}
	self.secondsLeft -= 1
	delegate?.didTick(secondsLeft)
	tickCount += 1
	}
	}

Introduction to Functional Reactive Programming

I. What is FRP?

C = A + B

ĐÓ CHÍNH LÀ REACTIVE PROGRAMMING!

1. Stream là gì?

2. Signal

3. FRP is Declarative

II. Why is FRP?

1. Search Issue on Github

2. Advantages

3. Search Issue on Github with Retry

4. Example 2 – Gesture Combination

5. What we can do

III. Reactive Thinking

1. FRP is hard, but it is SIMPLE

2. FRP is good trend

IV. How to FRP?

14 thoughts on “Introduction to Functional Reactive Programming”

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	class ReactiveShortViewController: UIViewController {

	override func viewDidLoad() {
	super.viewDidLoad()

	let pan = UIPanGestureRecognizer()
	pan.delegate = self
	let rotate = UIRotationGestureRecognizer()
	rotate.delegate = self
	view.gestureRecognizers = [pan, rotate]

	let panStarted = pan.rx_event.map { $0.state == .Began }.filter { $0 }
	let panEnded = pan.rx_event.map { $0.state == .Ended }.filter { $0 }

	let rotateStarted = rotate.rx_event.map { $0.state == .Began }.filter { $0 }
	let rotateEnded = rotate.rx_event.map { $0.state == .Ended }.filter { $0 }

	// condition: when both pan and pinch started & ended
	let bothGesturesStarted = Observable.zip(panStarted, rotateStarted) { ($0 && $1) }

	let bothGesturesEnded = Observable.of(panEnded, rotateEnded).merge()

	// Action
	bothGesturesStarted.subscribeNext { _ in
	// create a timer that ticks every second, until 3 or until pan and pinch ended
	let timer = Observable<Int>
	.timer(repeatEvery: 1)
	.take(3)
	.takeUntil(bothGesturesEnded)

	timer.subscribe(onNext: { count in
	print("tick: \(count)")
	}, onCompleted: {
	print("completed")
	})
	}
	}
	}

I. What is FRP?

C = A + B

ĐÓ CHÍNH LÀ REACTIVE PROGRAMMING!

1. Stream là gì?

2. Signal

3. FRP is Declarative

II. Why is FRP?

1. Search Issue on Github

2. Advantages

3. Search Issue on Github with Retry

4. Example 2 – Gesture Combination

5. What we can do

III. Reactive Thinking

1. FRP is hard, but it is SIMPLE

2. FRP is good trend

IV. How to FRP?

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14 thoughts on “Introduction to Functional Reactive Programming”

Leave a comment Cancel reply

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