Session 2 of Objective-C for the Irving iOS Jumpstart meetup. This evening we learned about creating UITableView's and programmatically setting the contents of their UITableViewCell's.

1. Objective-C Programming
Irving iOS Jumpstart

2. Objective-C
Programming
March 11, 2014

3. Overview of Today
• Quick 5 Realms Overview
• Objective-C Messaging
• Simple Programmatic UITableView Example
• Realistic UITableView Example

4. 5 Realms
for Learning iOS Development
Download full 5 Realms presentation at:
http://www.slideshare.net/irving-ios-jumpstart/5-realms

5. Why 5 Realms?
To the beginning iOS developer the formalities of
classes, frameworks, design patterns, and
learning an all new integrated development
environment can be overwhelming.

6. Why 5 Realms?
Knowing which realm you're having trouble in really
helps in finding the solution and getting unstuck in
your learning efforts.

7. 5 Realms
Design
Patterns
Objective-C
iOS SDK OOP
Xcode
IDE

8. Objective-C
Messaging
Objective-C

9. Defining Classes in
Objective-C
• Created via .h file and .m file
• All classes inherit from NSObject or another
class
Objective-C

10. @interface
@implementation
• @interface in an objective-c .h file
• @implementation in an objective-c .m file
• serves to separate the interface of a class
from its implementation.
Objective-C

11. @property
@synthesize
• Objective-C properties
• @property directive is used to create
properties on the class.
• Properties are accessed (read and set) via
automagically created setters and getters.
• In Xcode 5, optionally use @synthesize to
give instance variable a custom name
Objective-C

12. Objective-C Methods
• Class method
+ (return_type)methodName
• Instance method
- (return_type)methodName
• Distinguished by + or -
Objective-C

13. Objective-C Methods
- (void)addHotels
{
NSArray *hotels = [NSArray
arrayWithObjects:@"Aloft", @"The
W", @"Hilton", nil];
ourHotels = [NSArray
arrayWithArray:hotels];
}
- (return_type)methodName
Objective-C

14. Method With
Arguments
• this method has one argument
- (void)listOurHotelsUsingTitle:
(NSString *)title
{
NSLog(@"%@: %@", title,
ourHotels);
}
Objective-C

15. Method With
Arguments
• including sample method call below
- (void)listOurHotelsUsingTitle:(NSString *)title
{
NSLog(@"%@: %@", title, ourHotels);
}
!
[self listOurHotelsUsingTitle:@"Favorite Hotels"];
Objective-C

16. Foundation
Framework
• NSString - the Foundation Framework
class used to create string objects!
NSString *city = @"Irving";
iOS SDK

17. Foundation
Framework
NSString *myStory = [NSString
stringWithFormat:@"The brown fox
lives in %@", city];
//The brown fox lives in Irving
iOS SDK

18. Foundation
Framework
• NSString comparison
if ([city isEqualToString:@"Irving"]) {
NSLog(@"The two strings are the
same.");
} else {
NSLog(@"The two strings are
different.");
} //The two strings are the same.
iOS SDK

19. Foundation
Framework
• NSString comparison
if ([city isEqualToString:myStory]) {
NSLog(@"The two strings are the
same.");
} else {
NSLog(@"The two strings are
different.");
} //The two strings are different.
iOS SDK

20. Foundation
Framework
• NSArray - the Foundation Framework class
used to create array objects!
NSArray *hotels = [NSArray
arrayWithObjects:@"Aloft", @"The
W", @"Hilton", nil];
• An array is a set of ordered data items
iOS SDK

21. Foundation
Framework
NSArray *hotels = [NSArray
arrayWithObjects:@"Aloft", @"The
W", @"Hilton", nil];
• array index begins at zero, so an array with
3 elements are indexed 0, 1, and 2
NSLog(@"The hotel at index 1 in
this array is %@", [hotels
objectAtIndex:1]); // The W
iOS SDK

22. Foundation
Framework
• NSArray shortcut (objective-c literals)!
NSArray *hotels = @[@"Aloft",
@"The W", @"Hilton"];
• Cleaner and familiar syntax
iOS SDK

23. Foundation
Framework
• NSDictionary - the Foundation Framework
class used to store key and value pairs!
NSDictionary *hotels =
[NSDictionary
dictionaryWithObjectsAndKeys:@"5
star", @"Aloft", @"4 star", @"W",
@"5 star", @"Hilton", nil];
iOS SDK

24. Foundation
Framework
- (void)addHotelsWithRatings
{
NSDictionary *hotels = [NSDictionary
dictionaryWithObjectsAndKeys:@"5 star",
@"Aloft", @"4 star", @"W", @"5 star",
@"Hilton", nil];
!
NSLog(@"%@", hotels);
}
iOS SDK

25. Foundation
Framework
• NSDictionary shortcut (objective-c literals)!
NSDictionary *hotels =
@{@"Aloft":@"5 star", @"W":@"4
star", @"Hilton":@"5 star"};
• Cleaner syntax
iOS SDK

26. Foundation
Framework
• Mutable objects are changeable after
creation.
• Immutable objects cannot change once they
are created.
• Therefore additional methods exist on mutable
objects
iOS SDK

27. Mutable Objects
NSString (immutable)
NSMutableString (mutable)
NSArray
NSMutableArray
NSDictionary
NSMutableDictionary
iOS SDK

28. Mutable Objects
• NSMutableString Example
NSMutableString *iCanChange =
[NSMutableString
stringWithString:@"Hello..."];
NSLog(@"%@", [iCanChange
stringByAppendingString:@"world!"]);
// Hello...world!
iOS SDK

29. Mutable Objects
Download samples from github
!
https://github.com/jamesderry
iOS SDK

30. Programmatic
UITableView
Crosses several realms of IOS understanding.
!
!
!
Design
Patterns
Objective-C
iOS SDK OOP
Xcode
IDE

31. Programmatic
UITableView
• Xcode
• Storyboard - we'll build the view controller
storyboard containing a tableview
• IBOutlet - we'll use to grab a handle to the
tableview for manipulation in objective-c
code
Xcode
IDE

32. Programmatic
UITableView
• Design Patterns
• Model - View - Controller (MVC) pattern
• Delegate pattern
• Datasource pattern
Design
Patterns

33. Programmatic
UITableView
• Objective-C features
• Protocols
• Classes (UITableView and UITableViewCell)
• Dot syntax for cell properties
Objective-C

34. Programmatic
UITableView
• iOS SDK Features
• UIViewController (and view controller life
cycle)
• UIView
• UITableView and UITableViewCell
iOS SDK

35. Programmatic
UITableView Exercise
Create simple table view app

36. Programmatic
UITableView Exercise
Common Pitfalls
• forgetting to match the prototype cell identifier
name to the name used in your code
• forgetting to set the tableview datasource and
delegate

37. Thank You!
• Credits
• Wikipedia
• Programming in Objective-C by Stephen
Kochan
(any errors or omissions are probably mine)