Secrets of Objective-C

Objective-C is a fascinating language, bridging the object-oriented ideas of Smalltalk with the procedural underpinnings of C. This talk will explore how this curious intersection of programming paradigms influences the design and structure of modern OS X and iOS applications, drawing examples from some of the more obscure corners of Apple’s system frameworks.

Presented at the SendHub Tech Talk on 6/28/2014.
Video available here: https://www.youtube.com/watch?v=2KK_ay_mpGQ&list=PLC8Wr4QyrgQQpL7LkDd_GyvWFbXHM3rzd

Transcript

1. SECRETS OF OBJECTIVE-C
2. __bridge BETWEEN WORLDS
3. SMALLTALK & C
4. SMALLTALK 1972 ALAN KAY, DAN INGALLS, & ADELE GOLDBERG OBJECT-ORIENTED, LISP INSPIRED, MESSAGE PASSING
5. [object message:parameter]
7. C 1972 DENNIS RITCHIE PROCEDURAL, ALGOL INSPIRED
8. UNIX
9. CHOCOLATE + PEANUT BUTTER
10. PHILOSOPHER + A BAZOOKA
11. OBJECTIVE-C 1983 BRAD COX & TOM LOVE STATIC, DYNAMIC, WEAK
13. 
14. NS
16. STATIC, DYNAMIC, WEAK
17. id object = @"foo";
18. [object performSelector:@selector(bar)];
19. ?
20. nil, Nil, NULL
22. OBJECTIVE-C IS GETTING BETTER FASTER THAN ALMOST ANY OTHER LANGUAGE
23. ARC AUTOMATIC REFERENCE COUNTING
24. TIOBE "PROGRAMMING LANGUAGE OF THE YEAR: 2012"
26. OBJECTIVE-C: THE GOOD PARTS
29. KVC KEY-VALUE CODING
30. [person valueForKey:@"name"]
31. [person valueForKeyPath:@"spouse.name"]
32. [people valueForKeyPath:@"name"]
33. [people valueForKeyPath:@"@avg.salary"]
34. ▸ @count ▸ @sum ▸ @avg ▸ @max ▸ @min
35. objc/runtime.h
36. METHOD SWIZZLING ASSOCIATED OBJECTS DYNAMIC CLASS DEFINITION
37. @compatibility_alias
38. FRAMEWORKS
39. GCD GRAND CENTRAL DISPATCH
40. dispatch_queue_t queue = dispatch_queue_create("queue", NULL); dispatch_async(queue, ^{ // Do work asynchronously... dispatch_async(dispatch_get_main_queue(), ^{ // Return with result }); });
41. - (void)performActionWithObject:(id)object completionBlock:(void (^)(id result, NSError *error))block { // Do work asynchronously... if (block) { // Return with result block(result); } }
42. FOUNDATION THE STANDARD LIBRARY LANGUAGES WOULD kill FOR
43. LINGUISTICS APIS
44. NSSTRING
45. NSLINGUISTICTAGGER ▸ Token ▸ Lexical Class ▸ Name ▸ Lemma ▸ Language & Script
46. NSString *question = @"What is the weather in San Francisco?"; NSLinguisticTaggerOptions options = NSLinguisticTaggerOmitWhitespace | NSLinguisticTaggerOmitPunctuation | NSLinguisticTaggerJoinNames; NSLinguisticTagger *tagger = [[NSLinguisticTagger alloc] initWithTagSchemes: [NSLinguisticTagger availableTagSchemesForLanguage:@"en"] options:options]; tagger.string = question; [tagger enumerateTagsInRange:NSMakeRange(0, [question length]) scheme:NSLinguisticTagSchemeNameTypeOrLexicalClass options:options usingBlock: ^(NSString *tag, NSRange tokenRange, NSRange sentenceRange, BOOL *stop) { NSString *token = [question substringWithRange:tokenRange]; NSLog(@"%@: %@", token, tag); }];
47. WHAT: PRONOUN IS: VERB THE: DETERMINER WEATHER: NOUN IN: PREPOSITION SAN FRANCISCO: PLACENAME
48. LANGUAGE: ENGLISH
49. NSDATADETECTOR
50. ▸ Date ▸ Address ▸ Link ▸ Phone Number ▸ Transit Information
51. NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeAddress | NSTextCheckingTypePhoneNumber error:nil]; NSString *string = @"123 Main St. / (555) 555-5555"; [detector enumerateMatchesInString:string options:kNilOptions range:NSMakeRange(0, [string length]) usingBlock: ^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) { NSLog(@"Match: %@", result); }];
52. CFSTRINGTRANSFORM API FOR ICU TRANSFORMS
53. Énġlišh långuãge lẳcks iñterêßţing diaçrïtičş
55. {PIG FACE}
56. HELLO! ͜Μʹͪ͸! สวัสดี! م ر ح ب ا ! 䓟޷!
57. Hello! kon'nichiha! s̄wạs̄dī! mrḥbạ! nín hǎo!
58. Hello! kon'nichiha! swasdi! mrhba! nin hao!
59. (hello, kon'nichiha, swasdi, mrhba, nin, hao)
60. DATE & TIME PROGRAMMING
61. NSCALENDAR GREGORIAN, BUDDHIST, CHINESE, HEBREW, ISLAMIC, ISLAMIC CIVIL, JAPANESE, REPUBLIC OF CHINA, PERSIAN, INDIAN
62. NSCalendar *calendar = [NSCalendar currentCalendar]; NSDateComponents *dateComponents = [[NSDateComponents alloc] init]; dateComponents.weekday = 0; dateComponents.hour = 2; [calendar enumerateDatesStartingAfterDate:[NSDate date] matchingComponents:dateComponents options:NSCalendarMatchNextTime usingBlock: ^(NSDate *date, BOOL exactMatch, BOOL *stop) { NSLog(@"%@", date); }];
63. URL LOADING SYSTEM
64. NSURLREQUEST, NSURLRESPONSE, NSURLCONNECTION, NSURLSESSION, NSURLCACHE, NSHTTPCOOKIE, NSURLPROTOCOL, NSURLAUTHENTICATIONCHALLENGE
65. NSURL & NSURLCOMPONENTS RFC1808, RFC 2396, RFC3986
66. SORT DESCRIPTORS, PREDICATES, & EXPRESSIONS
67. NSSortDescriptor *firstNameSortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"firstName" ascending:YES selector:@selector(localizedStandardCompare:)]; NSSortDescriptor *lastNameSortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"lastName" ascending:YES selector:@selector(localizedStandardCompare:)]; NSSortDescriptor *ageSortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:NO];
68. NSPredicate *bobPredicate = [NSPredicate predicateWithFormat:@"firstName = 'Bob'"]; NSPredicate *smithPredicate = [NSPredicate predicateWithFormat:@"lastName = %@", @"Smith"]; NSPredicate *thirtiesPredicate = [NSPredicate predicateWithFormat:@"age >= 30"];
69. NSExpression *expression = [NSExpression expressionWithFormat:@"4 + 5 - 2**3"]; id value = [expression expressionValueWithObject:nil context:nil]; // => 1
70. NSERROR
71. @try{} @catch(NSException){} @finally{}
72. error:(NSError * __autoreleasing *)error
73. LOCALIZATION
74. INTERNATIONALIZATION
75. ACCESSIBILITY
76. ε-(´ɾʆ)
77. Dozens OF SYSTEM FRAMEWORKS
79. COMMUNITY
80. COCOAPODS DEPENDENCY MANAGER FOR OBJECTIVE-C cocoapods.org
81. 4638 PODS
82. ALCATRAZ XCODE PLUGIN MANAGER alcatraz.io
83. 116 PLUGINS
84. NS—
85. @MATTT
86. Thanks!