AutoLayoutDSL-Swift 1.0.2

You want to add pod 'AutoLayoutDSL-Swift', '~> 1.0' similar to the following to your Podfile:

target 'MyApp' do
  pod 'AutoLayoutDSL-Swift', '~> 1.0'
end

Then run a pod install inside your terminal, or from CocoaPods.app.

Alternatively to give it a test run, run the command:

pod try AutoLayoutDSL-Swift

AutoLayoutDSL-Swift 1.0.2

By
Yangyang Zhao

AutoLayoutDSL-Swift

AutoLayoutDSL-Swift is a straightforward swift DSL/extension for more convinient auto layout management

Features

[x] Mathematical operations +, -, *, /, ==, >=, <= for creating NSAutoLayoutConstraint
[x] Convinient infix operations =>, ~~>, ~~~> for adding constraints in chain mode

Requirements

iOS 7.0+
Xcode 6.3

Communication

If you need help, use Stack Overflow.
If you’d like to ask a general question, use Stack Overflow.
If you found a bug, open an issue.
If you have a feature request, open an issue.
If you want to contribute, submit a pull request.

Installation

**Embedded frameworks require a minimum deployment target of iOS 8

To use AutoLayoutDSL-Swift with a project targeting iOS 7, you must include all Swift files located inside the Source directory directly in your project. See the ‘Source File’ section for additional instructions.

Usage

Create an NSLayoutConstraints

import AutoLayoutDSL-Swift

view.left == parentView.left + 10
// is equal to 
NSLayoutConstraint(item: view, attribute: .Left, relatedBy: .Equal, toItem: parentView, attribute: .Left, multiplier: 1, constant:10


view.right >= parentView.right - 10
// is equal to 
NSLayoutConstraint(item: view, attribute: .Right, relatedBy: .GreaterThanOrEqual, toItem: parentView, attribute: .Right, multiplier: 1, constant:- 10

view.height == anotherView.height * 2
// is equal to 
NSLayoutConstraint(item: view, attribute: .Height, relatedBy: .Equal, toItem: anotherView, attribute: .Height, multiplier: 2, constant:0

view.height == anotherView.height / 2
// is equal to 
NSLayoutConstraint(item: view, attribute: .Height, relatedBy: .Equal, toItem: anotherView, attribute: .Height, multiplier: 0.5, constant:0


view.height == 100
// is equal to 
NSLayoutConstraint(item: view, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant:100

Add NSLayoutConstraints

// 4 NSLayoutConstraints were added and all their priority will be UILayoutPriorityRequired
self.view => self.redView.left == self.view.left + 10
        => self.redView.right == self.view.right - 10
        => self.redView.top == self.view.top + 30
        => self.redView.height == 100

// 4 NSLayoutConstraints were added 
// First two constraints' priorities will be UILayoutPriorityRequired
// Third constraint‘s priority will be UILayoutPriorityDefaultHigh
// Fourth constraint's priority will be UILayoutPriorityDefaultLow
self.view => self.redView.left == self.view.left + 10
        => self.redView.right == self.view.right - 10
        ~~> self.redView.top == self.view.top + 30
        ~~~> self.redView.height == 100

// If you want custom priority, you can write as belowing
var constaint = self.redView.left == self.view.left + 10
constraint.priority = UILayoutPriorityDefaultHigh - 1
self.view => constraint // => doesn't change priority

FAQ

When should I use AutoLayoutDSL-Swift?

If you are writting iOS project with Swift, and you want to create UI by manually writting code instead of using Storyboar, but you still want to take the advantage of AutoLayout to save you do the math for calculating the frame, and use automatically handling dynamic content, AutoLayoutDSL-Swift may be one of your choice to save a lot of lines creating instance of NSLayoutConstraint, also let the code to be more cleaner and more straightforward.

Acknowledgement

AutoLayoutDSL-Swift is inspired by AutoLayoutDSL, yet AutoLayoutDSL is written in Objective C++.

License

AutoLayoutDSL-Swift is released under the MIT license. See LICENSE for details.