Chapter 1 - notes

• When an iOS application starts, it puts a view on the screen. You can think of this view as the background on which everything else appears
• the groups at navigator are purely for the organization of files and do not correlate to the filesystem in any way. 
• XIB - pronounced "zib"
• When you build a project, the XIB file is compiled into a NIB file. 
• The bundle is a directory containing the application's executable and any resources the executable uses. 
• the labels and buttons are objects and objects have instance variables 
• View objects are visible to the user
• Model objects hold data and know nothing about the user interface. 
• Controller are the managers in an application. they keep the view and model objects in sync, control the "flow" of the application, and save the model objects out to the filesystem.
• Every iOS application has an "app delegate" object, and it is the primary controller of the application. 
• Each button needs to trigger a method. When a UIButton is tapped, it sends a message to another object. The object that is sent the message is called the target. The message is called the action. 
• What do IBOutlet and IBAction do in the declarations is that connect your controller and your view objects in the XIB file. 
• Command-1, Command-2, Command-3, Command-4
• App ID: The application identifier is a string that uniquely identifies your application on the App Store. Typically look like this: com.myname.GreatelookApp, where the name of the application follows the name of your company. 
• The App ID in your provisioning profile must match the bundle identifier of your application. A development profile wil have a wildcard character (*) for its App ID and therefore will match any bundle identifier. 
• Resources are things like images and sounds that are used by the application at runtime. XIB files, which are read in at runtime, are also resources. 
• When you dragged one image file onto the icon tile, two things happened. First, the image file added to your project. Second, one entry were made in the MyApp-Info.plist.
• The launch image has a specific role on iOS: it conveys to the user that the application is indeed launching and depicts the user interface that the user will interact with once the application has finished launching. One thing that launch image should not do is display a splash screen for your company or application.