Folder structure
In this section, we will understand the folder structure of our application as we know from the previous section that motion create <project name> sets up the directory structure with all the essential files to run a simple RubyMotion application. Let's walk through each one of them to have a precise understanding of their function:
- The
appfolder: This is the core of your application code; you will write most of your code in this folder. RubyMotion iterates in this folder and loads any.rbfile that it catches.Tip
If you want to keep your code somewhere else other than the
appdirectory, add the folder path to theRakefile. - The
app_delegate.rbfile in theappfolder: This file is at the heart of the RubyMotion application. If you are a little familiar with iOS development, this is the delegate file. A delegate is an object that usually reacts to some event in another object and/or can affect how another object behaves. There are various methods that can be implemented inUIApplicationDelegate. These methods are called during the different phases of an application, such as during the finish of its launch, during termination, when the application is low on memory, and during the occurrence of important changes. While the application is running, tracking its state transitions is one of the main jobs of the application delegate.App delegates use the method
application:didFinishLaunchingWithOptionsas the first entry point. This method is called after your application has been launched. When this method is called, your application is in the inactive state. A few other methods available are:applicationWillEnterForegroundapplicationWillTerminateapplication:shouldSaveApplicationStateapplication:shouldRestoreApplicationState
A full list of available methods can be obtained from the iOS developer library (http://developer.apple.com/library/ios). The good part here is that most of the methods are self-explanatory by their name. For example,
applicationWillEnterForegroundwill be called when your application is relaunched.Tip
We see that in some iOS 6 applications, the app is restored to the previous state; we can handle this in an application delegate.
- The
resourcesfolder: As the name suggests, theresourcesfolder contains static content, such as images, sounds, UI layouts, and icons that we use in our applications. - The
Specfolder: This folder contains automated test cases. RubyMotion supports a Ruby testing framework, Bacon; it is a small RSpec clone that is used for writing unit, functional, and UI tests. By default, it createsmain_spec.rbas an example. Rakefile: WithRakefilewe can configure our application name, resources, gems to be included, and the code location. We will discuss more aboutRakefilelater in this chapter.