Snappy is a light-weight layout framework which wraps AutoLayout with a nicer syntax. Snappy has its own layout DSL which provides a chainable way of describing your NSLayoutConstraints which results in layout code that is more concise and readable. Snappy supports both iOS and OS X.
> Snappy uses some Swift-only features like function overloading, so it cannot be used from Objective-C. Because of this we’ve chosen to swap prefixes from Masonry’s `mas_` to `snp_` so you can use both Masonry and Snappy in the same project.
_Due to the current lack of [proper infrastructure](http://cocoapods.org) for Swift dependency management, using Snappy in your project requires the following steps:_
1. Add Snappy as a [submodule](http://git-scm.com/docs/git-submodule) by opening the Terminal, `cd`-ing into your top-level project directory, and entering the command `git submodule add https://github.com/Masonry/Snappy.git`
2. Open the `Snappy` folder, and drag `Snappy.xcodeproj` into the file navigator of your Xcode project<sup>1</sup>.
3. In Xcode, navigate to the target configuration window by clicking on the blue project icon, and selecting the application target under the "Targets" heading in the sidebar.
4. In the tab bar at the top of that window, open the "General" panel.
5. Click on the `+` button in the "Embedded Binaries" group of the panel and select and add `Snappy.framework`.
<sup>1</sup><small>It's important you add Snappy as a subproject of your Xcode Project and not of a potential Xcode Workspace containing your project</small>
Under the hood Auto Layout is a powerful and flexible way of organising and laying out your views. However creating constraints from code is verbose and not very descriptive.
Imagine a simple example in which you want to have a view fill its superview but inset by 10 pixels on every side
Even with such a simple example the code needed is quite verbose and quickly becomes unreadable when you have more than 2 or 3 views.
Another option is to use Visual Format Language (VFL), which is a bit less long winded.
However the ASCII type syntax has its own pitfalls and its also a bit harder to animate as `NSLayoutConstraint.constraintsWithVisualFormat` returns an array.
## Prepare to meet your Maker!
Heres the same constraints created using ConstraintMaker
```swift
let padding = UIEdgeInsetsMake(10, 10, 10, 10)
view1.snp_makeConstraints { make in
make.top.equalTo(superview.snp_top).with.offset(padding.top) // with is an optional semantic filler
You can chain view attributes for increased readability:
```swift
// All edges but the top should equal those of the superview
make.left.right.and.bottom.equalTo(superview)
make.top.equalTo(otherView)
```
## Hold on for dear life
Sometimes you need modify existing constraints in order to animate or remove/replace constraints.
In Snappy there are a few different approaches to updating constraints.
#### 1. References
You can hold on to a reference of a particular constraint by assigning the result of a constraint make expression to a local variable or a class property.
You could also reference multiple constraints by storing them away in an array.
