Book Image

RubyMotion iOS Development Essentials

Book Image

RubyMotion iOS Development Essentials

Overview of this book

RubyMotion is a revolutionary toolchain for iOS app development. With RubyMotion, you can quickly develop and test native iOS apps for the iPhone and iPad, combining the expressiveness and simplicity of Ruby with the power of the iOS SDK. "RubyMotion iOS Development Essentials" is a hands-on guide for developing iOS apps using RubyMotion. With RubyMotion, you can eliminate the complexity and confusion associated with the development of iOS applications using Objective-C. We'll begin from scratch. Starting by installing RubyMotion, we'll build ourselves up to developing an app that uses the various device capabilities iOS has to offer. What's more, we'll even learn how to launch your app on the App Store! We'll also learn to use iOS SDK classes to create application views. Discover how to use the camera, geolocation, gestures, and other device capabilities to create engaging, interactive apps. We'll develop stunning user interfaces faster with the XCode interface builder and make web apps by using WebView. We'll then augment applications with RubyMotion gems, doing more by writing less code and learn how to write test cases for RubyMotion projects. Finally, we'll understand the app submission process to push your app to Apple's App Store With "RubyMotion iOS Development Essentials", we will learn how to create iOS apps with ease. At the end of each chapter we will have a tangible and running app, which utilizes the concepts we have learnt in that chapter.
Table of Contents (19 chapters)
RubyMotion iOS Development Essentials
Credits
About the Authors
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Interfacing with C and Objective-C


Although working with RubyMotion does not require one to learn Objective-C, or even C for that matter, sometimes when you want to use the iOS API, knowledge of its Ruby equivalent is beneficial. Objective-C is a superset of the C language. Objective-C methods can therefore accept and return C-language types.

Types

C language—and indirectly Objective-C—has a set of basic data types that are used in the iOS SDK APIs. In order to accept or return these data types, we need some equivalent data types for Ruby.

For example, let's create a function named foo that accepts a C integer type as a parameter and returns the some_number integer:

int foo(int some_number)
{
  return some_number;
}

So, if we want to call the preceding function from Ruby, we will require some equivalent Ruby type. Basic C types cannot be created from Ruby directly, but are automatically converted from and to equivalent Ruby types. You don't have to worry, RubyMotion will take care of this for...