Swift Reflectly

I learn how to make a reactive function, variable, and custom UI with closure for action. And I don't want to use "disposableBag". So I make this library from 2015. I have known my library not good. But I learn a lot about reactive programming.

Reactive

1. Promise: Function response in queue with operators
2. Variable: Variable reactive when it changed
3. UI Reactive: Button, Switch, Custome by Promise
4. Object Cache Reactive (Store, Pool): Cache object from request and make reactive change to update UI
5. Promise Await: wait multi response of Promise function

Operators

• throttle
• debounce
• filter
• distinct
• map
• flatMap

UIView

• Button
• Switch
• TextField
• TextView
• View Guesture
• View Constraint
• View properties
• ...

Issues

• promise.resolve()

Promise

        let promies: Promise<String?> = Promise<String?>()
        promies
            .map { $0 }
            .throttle(interval: 500)
            .debounce(interval: 200)
            .filter { ($0?.contains("3") ?? false) }
            .distinct()
            .observe { (result) in
                guard case let .success(vax) = result else { return }
                print("result success:", vax)
        }
        
        promies.resolve(nil)
        promies.resolve("334")
        promies.resolve("22")
        promies.resolve("44")
        promies.resolve("32")

Make a promise function

    func add(a: Int, b: Int) -> Future<Int> {
        let promise = Promise<Int>()
        promise.resolve(a + b)
        return promise
    }

Await

        do {
            let add1: Int = try await { self.add(a: 8, b: 9) }
            print("ober1:", add1)
            let add2: Int = try await { self.add(a: 5, b: 15) }
            print("ober2:", add2)
            print("add1 + add2:", add1 + add2)
        } catch let error {
            print("error:", error)
        }
        
        // Result:
        // ober1: 17
        // ober2: 20
        // add1 + add2: 37

Variable

let variable: Variable<Int> = Variable<Int>(0)
        
        variable
            .map { $0 + 1212 }
            .throttle(interval: 500)
            .debounce(interval: 200)
            .filter {$0 > 10}
            .observe { (result) in
                guard case let .success(vax) = result else { return }
                print("result success:", vax)
        }
        
        
        DispatchQueue.global(qos: .background).async {
            variable.value = 7
            usleep(100 * 1000)
            variable.value = 2
            usleep(100 * 1000)
            variable.value = 3
            usleep(100 * 1000)
            variable.value = 4
            usleep(300 * 1000) // waiting a bit longer than the interval
            variable.value = 5
            usleep(100 * 1000)
            variable.value = 6
            usleep(100 * 1000)
            variable.value = 7
            usleep(300 * 1000) // waiting a bit longer than the interval
            variable.value = 8
            usleep(100 * 1000)
            variable.value = 9
            usleep(100 * 1000)
            variable.value = 10
            usleep(100 * 1000)
            variable.value = 11
            usleep(100 * 1000)
            variable.value = 12
        }

UI Reactive

class ViewController: UIViewController {
    
    let button: Button = {
       let button = Button()
        button.frame = CGRect(x: 100, y: 100, width: 100, height: 50)
        button.setTitle("A", for: .normal)
        button.backgroundColor = .red
        return button
    }()
    
    override func loadView() {
        super.loadView()
        self.view.backgroundColor = .white
        self.view.addSubview(button)
        
        button
        .action()
        .debounce(interval: 200)
        .observe { [weak self] (event) in
            guard let `self` = self else { return}
            let vc = AViewController()
            vc.variable = self.variable
            self.navigationController?.pushViewController(vc, animated: true)
        }
    }
}

Reference

1. map, flatMap and compactMap
2. Under the hood of Futures and Promises in Swift
3. Promises by Google
4. RxSwift
5. Promise Javascript

Contact

• Email: caophuocthanh@gmail.com
• Site: https://onebuffer.com
• Linkedin: https://www.linkedin.com/in/caophuocthanh/