KitUI

KitUI is a set of extensions to UIKit to enable more functional and declarative style for building UIs. It enables developers to quickly and logically build layouts, but still allows you to reach down into UIKit to do the hard stuff.

Stack Views

KitUI enables Stack Views to be used to easily layout content. It uses simple functions called Horizontal and Vertical for initializing stack views

Vertical {
    UILabel("Heading")

    UILabel("Body")
}

Horizontal {
    UIImageView(UIImage(named: "Avatar"))

    UILabel("Name")
}

Buttons

Currently there's a simple button creation method which allows consumer to wrap any content in a button. I generally prefer this to attempt to use UIKit's limited UIButton style implementations

Button { pressed in
    UILabel("Action")
        .padding(.uniform(16))
        .backgroundColor(pressed.map { $0 ? UIColor.gray : UIColor.blue })
        .cornerRadius(4)
}

Modifiers

KitUI includes an array of chainable modifiers for building and customizing layouts inline. Currrently there are two types of modifiers, which dependending how you use the library could affect your usage

1. Wrapping modifiers - These wrap the current view in another containing view. So any subsequent code needs to understand these return a new separate view rather than the view they were called on

UILabel("Jon Snow")
    .padding(16) /// This is a wrapping modifier. It returns a new view wrapping the label

2. Mutating modifiers - These change the state or a property on the view they're called on, and return the same view. Calling the same mutating modifier with multiple reactive values could lead to unexpected behavior.

UILabel("text")
    .color(UIColor.blue) /// This is a mutating modifier, it just sets a value on the label

Reactivity

Many of KitUIs modifiers use ReactiveSwift to enable dynamic streams of values to be passed into them. I'm investigating using AsyncStreams a bit more. But a lot of KitUI is still powered by ReactiveCocoa under the hood