Building on the Basics in DHDeclarable

See Home if you need to reference the underlying implementation.

• Now that we understand the underlying implementation, utilizing this design principle and method we can improve how we re-use views on iOS.
• Let’s refer to the Stack View Example from the introduction:

  return UIStackView().declaredWith {​​​​​​​​​​​​​​​​​​​​​​​​​ stack in
    stack.axis = .vertical
    stack.distribution = .fill
    stack.spacing = 10
    stack.addArrangedSubview(...)
    stack.addArrangedSubview(...)
    stack.addArrangedSubview(...)
  }
  

• To make this view simpler, we can add extensions to UIKit objects: in this case UIStackView:

  extension Array where Element: UIView {​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
    func add(to stackView: UIStackView) {​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
            forEach {​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ view in
                stackView.addArrangedSubview(view)
            }​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
        }​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
    }​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
  

• Utilizing this extension, we can simplify the View syntax:

  UIStackView().declaredWith {​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ stack in
      stack.axis = .vertical
      stack.distribution = .fill
      stack.spacing = 10
      [
        UIView(),
      ].add(to: stack)
  }​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
  

• This extension now enables any list of UIView objects to be added to a stack view
• This will really help how hierarchical views can be created in UIKit, using a familiar Swift syntax: square brackets!
• Extensions are helpful tools for creating accessible, re-usable views in DHDeclarable.

Tip: Stack Views in DHDeclarable are a great alternative to using complicated Auto-Layout constraints

Continue learning about DHDeclarable in the next article: DHDeclarable Best Practices, or view the map.