1. The Life and Times of
UIViewController
Brandon Alexander
Wednesday, September 18, 13

2. Who am I
iOS Developer,Author, Speaker
Email: brandon.alexander@gmail.com
GTalk: brandon.alexander@gmail.com
Twitter/ADN: @balexander
Wednesday, September 18, 13

3. Design Pattern
A general reusable solution to a commonly
occurring problem within a given context in
software design
Wednesday, September 18, 13

4. MVC
• Model
• View
• Controller
Wednesday, September 18, 13

5. Controller
• Mediates between view and model
• Subclasses UIViewController
Wednesday, September 18, 13

6. Agenda
Wednesday, September 18, 13

7. Agenda
• UIViewController Lifecycle
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8. Agenda
• UIViewController Lifecycle
• Presenting other view controllers
Wednesday, September 18, 13

9. Agenda
• UIViewController Lifecycle
• Presenting other view controllers
• View Controller Containment
Wednesday, September 18, 13

10. Agenda
• UIViewController Lifecycle
• Presenting other view controllers
• View Controller Containment
• [REDACTED]
Wednesday, September 18, 13

11. Lifecycle
• Creation
• Interaction
• Destruction
Wednesday, September 18, 13

12. Creation
• NIB (or XIB)
• Storyboard
• In Code
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13. NIB
- (id) initWithNibName:(NSString *)n
bundle:(NSBundle *)b
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14. Storyboard
- (instancetype) initWithCoder:(NSCoder *)c
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15. Code
- (instancetype) init
- (instancetype) initWith...
- (void) loadView
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16. Creation Tips
• Wait for viewDidLoad for some startup
items
• Don’t reference vc.view before
viewDidLoad is called
• Use -[UIVC isViewLoaded]
• Use UIGestureRecognizer when possible
Wednesday, September 18, 13

17. Interaction
• Respond to user actions
• Delegate/Data Source Methods
• Respond to rotation events
• Respond to application notifications
• Navigate to other view controllers
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18. Important Methods
- (void) viewWillAppear:(BOOL)animated
- (void) viewDidAppear:(BOOL)animated
- (void) viewWillDisappear:(BOOL)animated
- (void) viewDidDisappear:(BOOL)animated
- (void) viewWillLayoutSubviews
- (void) viewDidLayoutSubviews
- (void) didReceiveMemoryWarning
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19. Rotation Support
• Info.plist shows all supported orientations
• Implement proper methods to support
each orientation in each view controller
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20. Interaction Tips
• Split Data Source methods out to helper
objects
• Keep the focus of the class in mind
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21. Destruction
• Implement dealloc when necessary
• Many existing UIKit classes aren’t ARCified
• Set delegate/dataSource properties to nil
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22. PresentingView
Controllers
! //Create VC
! UIViewController *vc = [UIViewController new];
!
! //Configure
! vc.modalPresentationStyle = UIModalPresentationFormSheet;
! vc.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
!
! //Present
! [self presentViewController:vc animated:YES completion:nil];
Wednesday, September 18, 13

23. Dismissing Presented
View Controllers
• Multiple Approaches
• Delegation
• Post to the responder chain
• Don’t have a view controller dismiss itself
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24. View Controller
Containment
• KeepsView Controller hierarchy the same
as the view hierarchy
• Helps solve the MassiveView Controller
anti-pattern
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25. Adding a ChildVC
- (void) displayContentController: (UIViewController*) content {
! [self addChildViewController:content];
! content.view.frame = [self frameForContentController];
! [self.view addSubview:self.currentClientView];
! [content didMoveToParentViewController:self];
}
Wednesday, September 18, 13

26. Removing a childVC
- (void) hideContentController: (UIViewController*) content {
! [content willMoveToParentViewController:nil];
! [content.view removeFromSuperview];
! [content removeFromParentViewController];
}
Wednesday, September 18, 13

27. Other Containment
Methods
- (BOOL) shouldAutomaticallyForwardAppearanceMethods
- (BOOL) shouldAutomaticallyForwardRotationMethods
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28. iOS 7
• CustomView Controller Transitions
• Different layout paradigms
• -automaticallyAdjustsScrollViewInsets
• UIKit Dynamics
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29. Architecture
• Avoid MassiveView Controllers
• Centralize networking code
• Controllers don’t have to be view
controllers
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30. Other Tricks
• Use nil-target actions in views
• Lazy load in container view controllers
• Don’t bother cleaning up in will(Dis)Appear
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31. Resources
• View Controller Programming Guide
• About Cocoa Auto Layout
• iOS 7 UI Transition Guide
Wednesday, September 18, 13

32. Questions
Wednesday, September 18, 13

33. Contact
Email: brandon.alexander@gmail.com
GTalk: brandon.alexander@gmail.com
Twitter/ADN: @balexander
Wednesday, September 18, 13