epicurious Anatomy of an ios app Robert Tolar Haining June 25, 2010 ConvergeSE

Transcription

1 epicurious Anatomy of an ios app Robert Tolar Haining June 25, 2010 ConvergeSE

2

3 + =

4 Prototype

5 iphone

6 ipad

7 Why iphone apps Simplicity Control Speed Revenue

8 Epicurious Defined as a Recipe Utility Cookbook + Shopping List

9 Challenges New language + framework Mobile Web Limited CPU + Memory Small screen Memory management

10 User Interface

11 Mobile What do you need on the go? Simple One core feature

12 How To Intuitive interface > Help Guides

13 Human Interface Guidelines Commonality across apps Familiarity

14 Physicality Physical metaphors pervasive Apps are fast - perception vs reality

15 Objective-C A Primer

16 File Types.h: header files.m: source files

17 Primitive Types int, long, NSInteger BOOL char float, double

18 Basic Types NSObject id NSString NSArray

19 Reviews : LoadedResource {! NSMutableArray *_reviewlist;! int _recipeid; (nonatomic, retain) NSMutableArray (nonatomic) int recipeid; -(id)initwithrecipeid:(int)recipeid; -(void)addreview:(review *)r; -(void)doneparsingreviews; -(BOOL)empty;

20 Reviews.h Class Reviews : LoadedResource {! NSMutableArray *_reviewlist;! int _recipeid; (nonatomic, retain) NSMutableArray (nonatomic) int recipeid; -(id)initwithrecipeid:(int)recipeid; -(void)addreview:(review *)r; -(void)doneparsingreviews; -(BOOL)empty;

21 Reviews.h Parent Class Reviews : LoadedResource {! NSMutableArray *_reviewlist;! int _recipeid; (nonatomic, retain) NSMutableArray (nonatomic) int recipeid; -(id)initwithrecipeid:(int)recipeid; -(void)addreview:(review *)r; -(void)doneparsingreviews; -(BOOL)empty;

22 Reviews.h Member Variable Declarations Reviews : LoadedResource {! NSMutableArray *_reviewlist;! int _recipeid; (nonatomic, retain) NSMutableArray (nonatomic) int recipeid; -(id)initwithrecipeid:(int)recipeid; -(void)addreview:(review *)r; -(void)doneparsingreviews; -(BOOL)empty;

23 Reviews.h Method Declarations Reviews : LoadedResource {! NSMutableArray *_reviewlist;! int _recipeid; (nonatomic, retain) NSMutableArray (nonatomic) int recipeid; -(id)initwithrecipeid:(int)recipeid; -(void)addreview:(review *)r; -(void)doneparsingreviews; -(BOOL)empty;

24 Method Declaration + (id)cannedsearchwithname:(nsstring *)aname forad:(ad *)ad;

25 Method Declaration Method Type Identifier + (id)cannedsearchwithname:(nsstring *)aname forad:(ad *)ad;

26 Method Declaration + (id)cannedsearchwithname:(nsstring *)aname forad:(ad *)ad; Return type

27 Method Declaration Method Signature Keywords + (id)cannedsearchwithname:(nsstring *)aname forad:(ad *)ad;

28 Method Declaration + (id)cannedsearchwithname:(nsstring *)aname forad:(ad *)ad; Parameter Types

29 Method Declaration + (id)cannedsearchwithname:(nsstring *)aname forad:(ad *)ad; Parameter Names

30 Method Declaration + (id)cannedsearchwithname:(nsstring *)aname forad:(ad *)ad; [Search cannedsearchwithname:description forad:ad];

31 Properties Expose member objects outside the class. Add to header int (copy) NSString (retain) NSMutableArray (readonly) NSDate *dateresultslastloaded; to your source resultlist, ateresultslastloaded;

32 Dot Notation These are equivalent: search.keyword [search setkeyword:@"taco"]; Also, these are equivalent: NSString *thekeyword = search.keyword; NSString *thekeyword = [search keyword];

33 NSString NSString *firstkeyword tacos"; NSString *secondkeyword = [NSString tacos", 3];

34 NSArray NSArray *arraya = [NSArray array]; NSArray *arrayb = [NSArray arraywithobjects:conde, nast, nil]; NSArray *arrayc = [[NSArray alloc] initwithobjects: converge, usc, nil];

35 Simple Iteration! for(nsstring *name in people){!! = name);! }

36 Cocoa Touch Cocoa: Framework for OSX Cocoa Touch: Framework for ios

37 Structure

38 App Delegate Root object Controls application

39 MVC Model: CoreData Views: UIView Controllers: UIViewController, NSXMLParser, etc.

40 Model: CoreData Schema-driven object graph management and persistence framework -Apple Simple GUI editor Powerful SQLite framework under the hood Generates basic code

41 Coredata: Example

42 Views: UIView One view per screen, composed of subviews. Text label, image, table, etc. UIWebView

43 UIView

44 UIView CGRect frame = CGRectMake(0,0,50,50); UIView *myview = [[UIView alloc] initwithframe:frame]; myview.backgroundcolor = [UIColor greencolor]; [self.view addsubview myview]; [myview release];

45 UIImageView UIImageView

46 UIImageView NSString *logoname epicurious_logo.png ; UIImage *logo = [UIImage imagenamed:logoname]; UIImageView *logoview = [[UIImageView alloc]!!!!!!! initwithimage:logo]; [self.view addsubview:logoview]; [logoview release];

47 UITableView

48 UITableView UITableView *cannedsearchtable = [[UITableView alloc] initwithframe:cgrectmake(10, 57, 300, 240) style:uitableviewstyleplain]; cannedsearchtable.delegate = self; cannedsearchtable.datasource = self; cannedsearchtable.rowheight = 40; cannedsearchtable.backgroundcolor = [UIColor clearcolor]; cannedsearchtable.separatorstyle = UITableViewCellSeparatorStyleNone; [self setview:cannedsearchtable]; [cannedsearchtable release];

49 UITableViewCell UITableViewCell

50 UITableViewCell - (UITableViewCell *)tableview:(uitableview *)tableview cellforrowatindexpath:(nsindexpath *)indexpath{ static NSString *CellIdentifierEdit HomeButtonCell *cell = (HomeButtonCell *)[tableview dequeuereusablecellwithidentifier:cellidentifieredit]; if (cell == nil) { cell = [[[HomeButtonCell alloc] initwithframe:cgrectzero reuseidentifier:thiscellidentifier] autorelease]; }! [cell setimageandtextforhomebutton:btn];! return cell; }

51 UILabel UILabel

52 UILabel UILabel *label = [[UILabel alloc] init]; label.text Healthy Lunches ; label.textcolor = [UIColor whitecolor]; label.backgroundcolor = [UIColor clearcolor]; label.alpha = 0.9; label.font = [UIFont fontwithname:@ Helvetica size:12]; [self.contentview addsubview:label]; [label release];

53 UIButton UIButton

54 UIButton UIButton *search = [UIButton buttonwithtype:uibuttontypecustom]; search.frame = CGRectMake(0, 330, 320, 75); [search setimage:[uiimage imagenamed:@"search_btn.png"] forstate:uicontrolstatenormal]; [search setimage:[uiimage imagenamed:@"search_btn_on.png"] forstate:uicontrolstatehighlighted]; [search addtarget:self action:@selector(showcustomsearch) forcontrolevents:uicontroleventtouchupinside]; [self.view addsubview:search];

55 UIWebView UIWebView

56 UIWebView self.infowebview = [[UIWebView alloc] init]; self.infowebview.delegate = [RecipeWebViewDelegate shareddelegate]; self.infowebview.backgroundcolor = [UIColor clearcolor]; NSString *html recipe information here</div></body></html>"; [self.infowebview loadhtmlstring:html baseurl:[nsurl URLWithString:@" [contentview addsubview:self.infowebview];

57 Controllers UIViewControllers Utilities: XML parsers, Downloaders, etc.

58 UINavigationController

59 UINavigationController UIViewController *rootvc = [[UIViewController alloc] init]; UINavigationController *navvc = [ [UINavigationController alloc] initwithrootviewcontroller:rootvc ]; // do something with navvc [navvc release]; [rootvc release];

60 UISplitViewController

61 UISplitViewController

62 UISplitViewController UISplitViewController *splitviewcontroller = [[UISplitViewController alloc] init]; splitviewcontroller.viewcontrollers = [NSArray arraywithobjects:masternavigationcontroller, detailnavigationcontroller, nil];! splitviewcontroller.view.backgroundcolor = [UIColor clearcolor]; [window addsubview:splitviewcontroller.view]; [splitviewcontroller release];

63 Animation Easy to use! Maintains physical metaphor.

64 Animation

65 Animation [scrollview setcontentoffset:cgpointmake(0,0) animated:no];

66 Animation [scrollview setcontentoffset:cgpointmake(-340,0) animated:no]; [UIView beginanimations:nil context:null]; [UIView setanimationduration:.25]; [scrollview setcontentoffset:cgpointmake(0,0) animated:no]; [UIView commitanimations];

67 ipad

68 Epicurious ipad

69 Navigational Structure iphone: UINavigationController ipad: UISplitViewController + two UINavigationControllers

70 Navigational Structure

71 Search

72 Classic Recipe View

73 Memory Management

74 No Garbage Collection

75 Overview Local objects should be released or autoreleased Member objects that are retained should be released in the dealloc method

76 Ownership Retention alloc retain copy new*

77 Ownership Release release autorelease

78 Real-world Metaphor? alloc: I make a cookie. retain: Lucy claims joint custody. release: Lucy decides she s not hungry. autorelease: I leave cookie on the table.

79

80 The Rule Within a given scope, if you cause an object to be retained, you re responsible for getting rid of it, either through release or autorelease.

81 dealloc You never call dealloc directly. Once retain count is zero, the system will call dealloc. However, you must implement dealloc.

82 dealloc -(void)dealloc{! [_keyword release];! [_attributes release]; //any other instance variables // or housecleaning!! [super dealloc]; }

83 Memory Leaks -(void)reset{! NSNumber *zero = [[NSNumber alloc] initwithint:0];! [self setcount:zero];! } BAD

84 Memory Leaks -(void)reset{! NSNumber *zero = [[NSNumber alloc] initwithint:0];! [self setcount:zero];! [zero release];! } GOOD!

85 Bad Release -(void)reset{! NSNumber *zero = [NSNumber numberwithint:0];! [self setcount:zero];! [zero release]; } BAD

86 Bad Release -(void)reset{! NSNumber *zero = [NSNumber numberwithint:0];! [self setcount:zero];! } GOOD!

87 Troubleshooting

88 XCode IDE for developing ios apps Includes Static Analyzer + Instruments

89

90 Static Analyzer Points out memory issues before they re a problem Build & Analyze

91 Instruments Object Allocations Memory Leaks Activity Monitor CoreData Time Profiler UI Automation & more!

92 Object Allocations Track heap memory Useful if you need to track down rogue memory or ensure an object is deallocated

93 Memory Leaks Checks for memory leaks duh.

94 Activity Monitor System Activity CPU Memory Disk Network

95 CoreData CoreData Filesystem Activity Fetches Cache misses Saves

96 Time Profiler Time-based sampling of processes

97 UI Automation Javascript based Simulates UI Speed through test to quickly detect issues

98 Threading

99 Threading Main thread belongs to the UI Everything else is you

100 Submission Process

101 Rejections Crashes Doesn t do what your App Store description claims Violates someone else s copyright Most notably, Apple s Violates HIG

102 Pre-submission First app? Setup your account well before you want to submit.

103 iads If you want your app to be free, consider iads. Expected to be huge money-maker.

104 Submission Expect a 3-7 day turnaround on your app. Can set availability date.

105 Summary

106 more? Tomorrow at 1pm: Talk on the more general process of design + development Resources developer.apple.com/iphone Stanford class - itunes.stanford.edu irc: freenode - #iphonedev me: convergese.kindofawesome.com