DuctTape 0.2.0

DuctTape 0.2.0

Maintained by Taiki Suzuki.

DuctTape 0.2.0


CI Status Version License Platform SwiftPM Carthage Language

📦 KeyPath dynamicMemberLookup based syntax sugar for Swift.

let label = UILabel().ductTape
    .text("Hello, World!!")

Above is same as below definition.

let label: UILabel = {
    let label = UILabel()
    label.numberOfLines = 0
    label.textColor = .red
    label.text = "Hello, World!!"
    return label


NSObject already has been compatible with DuctTape, so you can access .ductTape property like below.

let builder: Builder<UIView> = UIView().ductTape

If you access .ductTape, it returns Builder that provides setter of properties via KeyPath dynamicMemberLookup.

let view: UIView = UIView().ductTape

Finally, If you call .build(), Builder returns instance that has set property values.

If some objects are not compatible with DuctTape, there are two ways to use DuctTape.

  1. Use DuctTapeCompatible
class Dog: DuctTapeCompatible {
    var name: String

let dog = Dog().ductTape
  1. Use Builder directly
class Dog {
    var name: String

let dog = Builder(Dog())


class ViewController: UIViewController {

    let flowLayout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        .itemSize(CGSize(width: 100, height: 100))

    lazy var collectionView: UICollectionView = UICollectionView(frame: .zero,
                                                                 collectionViewLayout: flowLayout)
        .reinforce {
            $0.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")

    override func viewDidLoad() {

            view.topAnchor.constraint(equalTo: collectionView.topAnchor),
            view.leadingAnchor.constraint(equalTo: collectionView.leadingAnchor),
            view.trailingAnchor.constraint(equalTo: collectionView.trailingAnchor),
            view.bottomAnchor.constraint(equalTo: collectionView.bottomAnchor)


  • Xcode 11
  • macOS 10.10
  • iOS 9.0
  • tvOS 10.0
  • watchOS 3.0



DuctTape is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod "DuctTape"


If you’re using Carthage, simply add DuctTape to your Cartfile:

github "marty-suzuki/DuctTape"

Swift Package Manager

Simply add the following line to your Package.swift:

.package(url: "https://github.com/marty-suzuki/DuctTape.git", from: "version")


DuctTape is released under the MIT License.