Relative constraints with tags 🔥

Really often we have to create some views with constraints related to each other 😃

Before

Before that release we had to create a variable with view somewhere outside, like this

let someView = UView()

then we used it with other views to make relative constraints

UView {
    someView.size(200).background(.red).centerInSuperview()
    UView().size(100).background(.cyan).centerXInSuperview().top(to: someView)
    UView().size(100).background(.purple).centerXInSuperview().bottom(to: someView)
    UView().size(100).background(.yellow).centerYInSuperview().right(to: someView)
    UView().size(100).background(.green).centerYInSuperview().left(to: someView)
}

Now

But since now we can easily rely just to view's tag

UView {
    UView().size(200).background(.red).centerInSuperview().tag(7)
    UView().size(100).background(.cyan).centerXInSuperview().top(to: 7)
    UView().size(100).background(.purple).centerXInSuperview().bottom(to: 7)
    UView().size(100).background(.yellow).centerYInSuperview().right(to: 7)
    UView().size(100).background(.green).centerYInSuperview().left(to: 7)
}

Even order doesn't matter 🤗

UView {
    UView().size(100).background(.cyan).centerXInSuperview().top(to: 7)
    UView().size(100).background(.purple).centerXInSuperview().bottom(to: 7)
    UView().size(100).background(.yellow).centerYInSuperview().right(to: 7)
    UView().size(100).background(.green).centerYInSuperview().left(to: 7)
    UView().size(200).background(.red).centerInSuperview().tag(7)
}

You even can add view later and all related views will immediately stick to it once it's added 🚀

let v = UView {
    UView().size(100).background(.cyan).centerXInSuperview().top(to: 7)
    UView().size(100).background(.purple).centerXInSuperview().bottom(to: 7)
    UView().size(100).background(.yellow).centerYInSuperview().right(to: 7)
    UView().size(100).background(.green).centerYInSuperview().left(to: 7)
}
DispatchQueue.main.asyncAfter(deadline: .now() + 5) {
    UIView.animate(withDuration: 1) {
        v.body {
            UView().size(200).background(.red).centerInSuperview().tag(7)
        }
    }
}