UIViewBuilder syntactic sugar

gistfile1.txt

import UIKit

///
///Declaration
///
protocol UIViewBuilder: AnyObject {}

extension UIViewBuilder where Self: UIView {
    init(_ build: ((Self) -> Void)) {
        self.init()
        build(self)
    }
}

extension UIViewBuilder {
    func configure(_ build: ((Self) -> Void)) -> Self {
        build(self)
        return self
    }
}

extension UIView: UIViewBuilder {}
extension UIViewController: UIViewBuilder {}


/// ViewController components creation
class ViewController: UIViewController {
    let coloredSubView = UIView {
        $0.backgroundColor = .orange
    }
    
    let button = UIButton(type: .system).configure {
        $0.backgroundColor = .orange
        $0.setTitle("Action", for: .normal)
    }
}

///Preview usefull for prototyping
#Preview {
    UIButton(type: .system).configure {
        $0.backgroundColor = .orange
        $0.setTitle("Action", for: .normal)
    }
}

/// Functional components composition example
#Preview {
    UIStackView { stack in
        stack.addArrangedSubview(UIButton(type: .system).configure {
            $0.backgroundColor = .red
            $0.setTitle("Red", for: .normal)
        })
        
        stack.addArrangedSubview(UIButton(type: .system).configure {
            $0.backgroundColor = .yellow
            $0.setTitle("Yellow", for: .normal)
        })
        
        stack.addArrangedSubview(UIButton(type: .system).configure {
            $0.backgroundColor = .green
            $0.setTitle("Green", for: .normal)
        })
        
    }
}