Some tips about coding in swift efficiently and elegantly

Funny Swift.playground

This playground file has some tips about how to write funny swift which saves your time and fingers.

Extension for Selector:

private extension Selector {
    static let btnTapped = #selector(ViewController.btnTapped(btn:))
}

btn.addTarget(self, action: .btnTapped, for: .touchUpInside)

Extension for Notification.Name

extension Notification.Name {
    static let changed = NSNotification.Name(rawValue: "changed")
}

NotificationCenter.default.post(name: .changed, object: nil)

To eliminate nil check with flatMap

if city != nil {
    para["city"] = city	
}

city.flatMap { para["city"] = $0 }

Managing multiple storyboards

user.storyboard
topic.storyboard
...

let userVC = AppStoryboard.user.viewController(UserViewController.self)

let topicVC = AppStoryboard.topic.viewController("TopicViewController")

Extension reduce repeat code

let p = CGPoint(x:10, y:10.1)
let r = CGRect(x:10, y:10, width:100, height:100)

//lazy code
let p = CGPoint(10, 10.1)
let r = CGRect(10, 10, 100, 100)

Extension to code in chain style

let view = UIView()
    .backgroundColor(.white)
    .tag(1)
    ...

Use & to combine protocols

typealias SpeakAble = SpeakStringAble & SpeakCharacterAble

Array subscripts

var arr = [1, 2, 3]
arr[[0, 2]] //print [1, 3]

The Dao of Protocol.playground

This playground file is about basic Protocol and Protocol Oriented Programming.

Isolate builder code

let btn = UIButton() {
    $0.frame = CGRect(x: 10, y: 10, width: 44, height: 44)
    $0.backgroundColor = .red
    ...
}

Keyboard observer

final class ViewController: UIViewController {
    ...
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        addKeyboardObservers()
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        
        removeKeyboardObservers()
    }
}

Default implementation for Active Record

extension User: RemoteFetchable { }

User.request(RemoteResouce("api.example.com", "/users", .get),
    success: { data in
        
    },
    failure: { err in
        
    })

Extension for specific generic

extension Callable where Self.PhoneNumberType : SignedInteger {
    func call() {
        print("this is a number", phone)
    }
}