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
   

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2. __bridge BETWEEN WORLDS
   

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3. SMALLTALK & C
   

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4. SMALLTALK
   1972
   ALAN KAY, DAN INGALLS,
   & ADELE GOLDBERG
   OBJECT-ORIENTED, LISP INSPIRED, MESSAGE PASSING
   

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5. [object message:parameter]
   

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7. C
   1972
   DENNIS RITCHIE
   PROCEDURAL, ALGOL INSPIRED
   

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8. UNIX
   

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9. CHOCOLATE +
   PEANUT BUTTER
   

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10. PHILOSOPHER +
    A BAZOOKA
    

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11. OBJECTIVE-C
    1983
    BRAD COX & TOM LOVE
    STATIC, DYNAMIC, WEAK
    

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13. 
    

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14. NS
    

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16. STATIC, DYNAMIC, WEAK
    

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17. id object = @"foo";
    

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18. [object performSelector:@selector(bar)];
    

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19. ?
    

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20. nil, Nil, NULL
    

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22. OBJECTIVE-C IS GETTING
    BETTER FASTER THAN
    ALMOST ANY OTHER
    LANGUAGE
    

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23. ARC
    AUTOMATIC REFERENCE COUNTING
    

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24. TIOBE
    "PROGRAMMING LANGUAGE OF THE YEAR: 2012"
    

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26. OBJECTIVE-C:
    THE GOOD PARTS
    

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29. KVC
    KEY-VALUE CODING
    

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30. [person valueForKey:@"name"]
    

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31. [person valueForKeyPath:@"spouse.name"]
    

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32. [people valueForKeyPath:@"name"]
    

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33. [people valueForKeyPath:@"@avg.salary"]
    

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34. ▸ @count
    ▸ @sum
    ▸ @avg
    ▸ @max
    ▸ @min
    

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35. objc/runtime.h
    

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36. METHOD SWIZZLING
    ASSOCIATED OBJECTS
    DYNAMIC CLASS DEFINITION
    

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37. @compatibility_alias
    

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38. FRAMEWORKS
    

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39. GCD
    GRAND CENTRAL DISPATCH
    

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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
    });
    });
    

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41. - (void)performActionWithObject:(id)object
    completionBlock:(void (^)(id result, NSError *error))block {
    // Do work asynchronously...
    if (block) {
    // Return with result
    block(result);
    }
    }
    

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42. FOUNDATION
    THE STANDARD LIBRARY LANGUAGES WOULD
    kill FOR
    

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43. LINGUISTICS APIS
    

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44. NSSTRING
    

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45. NSLINGUISTICTAGGER
    ▸ Token
    ▸ Lexical Class
    ▸ Name
    ▸ Lemma
    ▸ Language & Script
    

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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);
    }];
    

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47. WHAT: PRONOUN
    IS: VERB
    THE: DETERMINER
    WEATHER: NOUN
    IN: PREPOSITION
    SAN FRANCISCO: PLACENAME
    

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48. LANGUAGE: ENGLISH
    

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49. NSDATADETECTOR
    

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50. ▸ Date
    ▸ Address
    ▸ Link
    ▸ Phone Number
    ▸ Transit Information
    

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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);
    }];
    

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52. CFSTRINGTRANSFORM
    API FOR ICU TRANSFORMS
    

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53. Énġlišh långuãge lẳcks iñterêßţing diaçrïtičş
    

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55. {PIG FACE}
    

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56. HELLO! ͜Μʹͪ͸! สวัสดี! م
    ر
    ح
    ب
    ا ! 䓟޷!
    

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57. Hello! kon'nichiha! s̄wạs̄dī! mrḥbạ! nín hǎo!
    

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58. Hello! kon'nichiha! swasdi! mrhba! nin hao!
    

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59. (hello, kon'nichiha, swasdi, mrhba, nin, hao)
    

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60. DATE & TIME
    PROGRAMMING
    

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61. NSCALENDAR
    GREGORIAN, BUDDHIST, CHINESE, HEBREW,
    ISLAMIC, ISLAMIC CIVIL, JAPANESE,
    REPUBLIC OF CHINA, PERSIAN, INDIAN
    

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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);
    }];
    

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63. URL LOADING
    SYSTEM
    

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64. NSURLREQUEST, NSURLRESPONSE,
    NSURLCONNECTION, NSURLSESSION,
    NSURLCACHE, NSHTTPCOOKIE,
    NSURLPROTOCOL,
    NSURLAUTHENTICATIONCHALLENGE
    

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65. NSURL & NSURLCOMPONENTS
    RFC1808, RFC 2396, RFC3986
    

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66. SORT DESCRIPTORS,
    PREDICATES, &
    EXPRESSIONS
    

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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];
    

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68. NSPredicate *bobPredicate =
    [NSPredicate predicateWithFormat:@"firstName = 'Bob'"];
    NSPredicate *smithPredicate =
    [NSPredicate predicateWithFormat:@"lastName = %@", @"Smith"];
    NSPredicate *thirtiesPredicate =
    [NSPredicate predicateWithFormat:@"age >= 30"];
    

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69. NSExpression *expression =
    [NSExpression expressionWithFormat:@"4 + 5 - 2**3"];
    id value = [expression expressionValueWithObject:nil
    context:nil];
    // => 1
    

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70. NSERROR
    

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71. @try{}
    @catch(NSException){}
    @finally{}
    

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72. error:(NSError * __autoreleasing *)error
    

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73. LOCALIZATION
    

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74. INTERNATIONALIZATION
    

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75. ACCESSIBILITY
    

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76. ε-(´ɾʆ)
    

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77. Dozens OF
    SYSTEM
    FRAMEWORKS
    

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79. COMMUNITY
    

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80. COCOAPODS
    DEPENDENCY MANAGER FOR OBJECTIVE-C
    cocoapods.org
    

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81. 4638 PODS
    

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82. ALCATRAZ
    XCODE PLUGIN MANAGER
    alcatraz.io
    

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83. 116 PLUGINS
    

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84. NS—
    

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85. @MATTT
    

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86. Thanks!
    

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