Book Image

Swift Essentials - Second Edition

By : Alex Blewitt
Book Image

Swift Essentials - Second Edition

By: Alex Blewitt

Overview of this book

Swift was considered one of the biggest innovations last year, and certainly with Swift 2 announced at WWDC in 2015, this segment of the developer space will continue to be hot and dominating. This is a fast-paced guide to provide an overview of Swift programming and then walks you through in detail how to write iOS applications. Progress through chapters on custom views, networking, parsing and build a complete application as a Git repository, all by using Swift as the core language
Table of Contents (17 chapters)
Swift Essentials Second Edition
About the Author
About the Reviewer

Creating new views by subclassing UIView

Although the xib files offer a mechanism to customize classes, the majority of UIKit views outside of standard frameworks are implemented in custom code. This makes it easier to reason what the intrinsic size should be as well as to receive code patches and understand diffs from version control systems. The downside of this approach is when using Auto Layout, writing the constraints can be a challenge and the intrinsic sizes are often misreported or return the unknown value: (-1,-1).

A custom view can be implemented as a subclass of UIView. Subclasses of UIView are expected to have two initializers, one that takes a frame:CGRect and one that takes a coder:NSCoder. The frame is generally used in code, and the rect specifies the position on screen (0,0 is the top-left) along with the width and height. The coder is used when deserializing from a xib file.

To allow custom subclasses to either be used in Interface Builder or instantiated from code, it is...