NSCoder Madrid: Talk about how to use Mantle and AFNetworking together. You can find the sample code here https://github.com/gonzalezreal/ReadingList

1. Better Web Clients with
Mantle & AFNetworking

2. Guillermo González
@gonzalezreal

3. Mantle
Model framework for Cocoa and Cocoa Touch

4. https://github.com/github/Mantle

5. Makes it easy to write a
simple model layer

6. Gets rid of boilerplate code

7. Gets rid of boilerplate code
-hash

8. Gets rid of boilerplate code
-hash
-isEqual:

9. Gets rid of boilerplate code
-hash
-isEqual:
NSCopying

10. Gets rid of boilerplate code
-hash
-isEqual:
NSCopying
NSCoding

11. Example: Book Model
@interface TGRBook : MTLModel
!
@property
@property
@property
@property
@property
@property
@property
!
@end
(copy,
(copy,
(copy,
(copy,
(copy,
(copy,
(copy,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
readonly)
readonly)
readonly)
readonly)
readonly)
readonly)
readonly)
NSString *author;
NSString *overview;
NSArray *genres;
NSDate *releaseDate;
NSNumber *identifier;
NSString *title;
NSURL *coverURL;

12. Example: Book Model
@interface TGRBook : MTLModel
!
@property
@property
@property
@property
@property
@property
@property
(copy,
(copy,
(copy,
(copy,
(copy,
(copy,
(copy,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
nonatomic,
readonly)
readonly)
readonly)
readonly)
readonly)
readonly)
readonly)
NSString *author;
NSString *overview;
NSArray *genres;
NSDate *releaseDate;
NSNumber *identifier;
NSString *title;
NSURL *coverURL;
!
@end
Prefer immutable model objects

14. NSError *error = nil;
TGRBook *book = [TGRBook modelWithDictionary:@{
@"title" : @"The Sandman",
@"author" : @"Neil Gaiman",
@"genres" : @[@"Graphic Novels", @"Fantasy"],
...
} error:&error];

15. NSError *error = nil;
TGRBook *book = [TGRBook modelWithDictionary:@{
@"title" : @"The Sandman",
@"author" : @"Neil Gaiman",
@"genres" : @[@"Graphic Novels", @"Fantasy"],
...
} error:&error];
TGRBook *anotherBook = [book copy];

16. NSError *error = nil;
TGRBook *book = [TGRBook modelWithDictionary:@{
@"title" : @"The Sandman",
@"author" : @"Neil Gaiman",
@"genres" : @[@"Graphic Novels", @"Fantasy"],
...
} error:&error];
TGRBook *anotherBook = [book copy];
[NSKeyedArchiver archiveRootObject:book toFile:@"my_file"];

17. NSError *error = nil;
TGRBook *book = [TGRBook modelWithDictionary:@{
@"title" : @"The Sandman",
@"author" : @"Neil Gaiman",
@"genres" : @[@"Graphic Novels", @"Fantasy"],
...
} error:&error];
TGRBook *anotherBook = [book copy];
[NSKeyedArchiver archiveRootObject:book toFile:@"my_file"];
TGRBook *b = [NSKeyedUnarchiver unarchiveObjectWithFile:@"my_file"];

18. (lldb) po book

19. (lldb) po book
$0 = 0x0a349050 <TGRBook: 0xa349050> {
author = "Neil Gaiman, Sam Keith & Mike Dringenberg";
coverURL = "http://a4.mzstatic.com/us/r30/Publication/...";
genres =
(
"Graphic Novels",
Books,
"Comics & Graphic Novels"
);
identifier = 554016043;
overview = "<p>NEW YORK TIMES bestselling author Neil Gaiman's...";
releaseDate = "2012-08-21 05:00:00 +0000";
title = "The Sandman, Vol. 1: Preludes & Nocturnes (New Edition)";
}

20. All this just by subclassing MTLModel

21. Our Book Model could
have a JSON representation

22. Our Book Model could
have a JSON representation
{
...
"artistName": "Neil Gaiman, Sam Keith & Mike Dringenberg",
"description": "<p>NEW YORK TIMES bestselling author...",
"genres": ["Graphic Novels", "Books", "Comics & Graphic Novels"],
"releaseDate": "2012-08-21T07:00:00Z",
"trackId": 554016043,
"trackName": "The Sandman, Vol. 1: Preludes & Nocturnes (New Edition)",
"artworkUrl100": "http://a4.mzstatic.com/us/r30/Publication/...",
...
}

23. Our Book Model could
have a JSON representation
{
...
"artistName": "Neil Gaiman, Sam Keith & Mike Dringenberg",
"description": "<p>NEW YORK TIMES bestselling author...",
"genres": ["Graphic Novels", "Books", "Comics & Graphic Novels"],
"releaseDate": "2012-08-21T07:00:00Z",
"trackId": 554016043,
"trackName": "The Sandman, Vol. 1: Preludes & Nocturnes (New Edition)",
"artworkUrl100": "http://a4.mzstatic.com/us/r30/Publication/...",
...
}
This is how iTunes represents media (including books)

24. Our Book Model could
have a JSON representation
{
...
"artistName": "Neil Gaiman, Sam Keith & Mike Dringenberg",
"description": "<p>NEW YORK TIMES bestselling author...",
"genres": ["Graphic Novels", "Books", "Comics & Graphic Novels"],
"releaseDate": "2012-08-21T07:00:00Z",
"trackId": 554016043,
"trackName": "The Sandman, Vol. 1: Preludes & Nocturnes (New Edition)",
"artworkUrl100": "http://a4.mzstatic.com/us/r30/Publication/...",
...
}
This is how iTunes represents media (including books)
See http://www.apple.com/itunes/affiliates/resources/
documentation/itunes-store-web-service-search-api.html

25. MTLJSONSerializing protocol
@interface TGRBook : MTLModel <MTLJSONSerializing>

26. MTLJSONSerializing protocol
@interface TGRBook : MTLModel <MTLJSONSerializing>
Specify how to map properties to JSON
keypaths

27. MTLJSONSerializing protocol
@interface TGRBook : MTLModel <MTLJSONSerializing>
Specify how to map properties to JSON
keypaths
Specify how to convert a JSON value to a
property key

28. + (NSDictionary *)JSONKeyPathsByPropertyKey {
return @{
@"author" : @"artistName",
@"overview" : @"description",
@"identifier" : @"trackId",
@"title" : @"trackName",
@"coverURL" : @"artworkUrl100"
};
}

29. + (NSDictionary *)JSONKeyPathsByPropertyKey {
return @{
@"author" : @"artistName",
@"overview" : @"description",
@"identifier" : @"trackId",
@"title" : @"trackName",
@"coverURL" : @"artworkUrl100"
};
}
Only properties with a corresponding ivar

30. + (NSDictionary *)JSONKeyPathsByPropertyKey {
return @{
@"author" : @"artistName",
@"overview" : @"description",
@"identifier" : @"trackId",
@"title" : @"trackName",
@"coverURL" : @"artworkUrl100"
};
}
Only properties with a corresponding ivar
Property keys not present in the dictionary are
assumed to match the JSON

31. + (NSValueTransformer *)releaseDateJSONTransformer {
return [MTLValueTransformer reversibleTransformerWithForwardBlock:^(NSString *str) {
return [self.dateFormatter dateFromString:str];
} reverseBlock:^(NSDate *date) {
return [self.dateFormatter stringFromDate:date];
}];
}
!
+ (NSValueTransformer *)coverURLJSONTransformer {
return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
}

32. + (NSValueTransformer *)releaseDateJSONTransformer {
return [MTLValueTransformer reversibleTransformerWithForwardBlock:^(NSString *str) {
return [self.dateFormatter dateFromString:str];
} reverseBlock:^(NSDate *date) {
return [self.dateFormatter stringFromDate:date];
}];
}
!
+ (NSValueTransformer *)coverURLJSONTransformer {
return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
}
+<key>JSONTransformer
methods

33. + (NSValueTransformer *)releaseDateJSONTransformer {
return [MTLValueTransformer reversibleTransformerWithForwardBlock:^(NSString *str) {
return [self.dateFormatter dateFromString:str];
} reverseBlock:^(NSDate *date) {
return [self.dateFormatter stringFromDate:date];
}];
}
!
+ (NSValueTransformer *)coverURLJSONTransformer {
return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
}
+<key>JSONTransformer
MTLValueTransformer
methods
is a block-based value transformer

34. + (NSValueTransformer *)releaseDateJSONTransformer {
return [MTLValueTransformer reversibleTransformerWithForwardBlock:^(NSString *str) {
return [self.dateFormatter dateFromString:str];
} reverseBlock:^(NSDate *date) {
return [self.dateFormatter stringFromDate:date];
}];
}
!
+ (NSValueTransformer *)coverURLJSONTransformer {
return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
}
+<key>JSONTransformer
MTLValueTransformer
methods
is a block-based value transformer
Predefined transformers: MTLURLValueTransformerName and
MTLBooleanValueTransformerName

35. Mapping JSON child objects

36. Mapping JSON child objects
@interface TGRUser : MTLModel <MTLJSONSerializing>
!
@property (copy, nonatomic, readonly) NSArray *purchasedBooks;
@property (copy, nonatomic, readonly) TGRBook *nowReading;
!
@end

37. Mapping JSON child objects
@interface TGRUser : MTLModel <MTLJSONSerializing>
!
@property (copy, nonatomic, readonly) NSArray *purchasedBooks;
@property (copy, nonatomic, readonly) TGRBook *nowReading;
!
@end
+ (NSValueTransformer *)purchasedBooksJSONTransformer {

38. Mapping JSON child objects
@interface TGRUser : MTLModel <MTLJSONSerializing>
!
@property (copy, nonatomic, readonly) NSArray *purchasedBooks;
@property (copy, nonatomic, readonly) TGRBook *nowReading;
!
@end
+ (NSValueTransformer *)purchasedBooksJSONTransformer {
return [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];

39. Mapping JSON child objects
@interface TGRUser : MTLModel <MTLJSONSerializing>
!
@property (copy, nonatomic, readonly) NSArray *purchasedBooks;
@property (copy, nonatomic, readonly) TGRBook *nowReading;
!
@end
+ (NSValueTransformer *)purchasedBooksJSONTransformer {
return [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
}

40. Mapping JSON child objects
@interface TGRUser : MTLModel <MTLJSONSerializing>
!
@property (copy, nonatomic, readonly) NSArray *purchasedBooks;
@property (copy, nonatomic, readonly) TGRBook *nowReading;
!
@end
+ (NSValueTransformer *)purchasedBooksJSONTransformer {
return [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
}

41. Mapping JSON child objects
@interface TGRUser : MTLModel <MTLJSONSerializing>
!
@property (copy, nonatomic, readonly) NSArray *purchasedBooks;
@property (copy, nonatomic, readonly) TGRBook *nowReading;
!
@end
+ (NSValueTransformer *)purchasedBooksJSONTransformer {
return [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
}
+ (NSValueTransformer *)nowReadingJSONTransformer {

42. Mapping JSON child objects
@interface TGRUser : MTLModel <MTLJSONSerializing>
!
@property (copy, nonatomic, readonly) NSArray *purchasedBooks;
@property (copy, nonatomic, readonly) TGRBook *nowReading;
!
@end
+ (NSValueTransformer *)purchasedBooksJSONTransformer {
return [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
}
+ (NSValueTransformer *)nowReadingJSONTransformer {
return [NSValueTransformer mtl_JSONDictionaryTransformerWithModelClass:TGRBook.class];

43. MTLJSONAdapter
TGRBook *book = [MTLJSONAdapter modelOfClass:TGRBook.class
fromJSONDictionary:JSONDictionary
error:&error];
!
!
NSDictionary *dictionary = [MTLJSONAdapter JSONDictionaryFromModel:book];

44. Do we still need Core Data?

45. Do we still need Core Data?
Of course!

46. Do we still need Core Data?
Of course!
Memory efficiency with large datasets

47. Do we still need Core Data?
Of course!
Memory efficiency with large datasets
NSFetchRequest is cool!

48. Do we still need Core Data?
Of course!
Memory efficiency with large datasets
NSFetchRequest is cool!
Mantle and Core Data can work together

49. An entity for our Book Model

50. MTLManagedObjectSerializing protocol
@interface TGRBook : MTLModel <MTLManagedObjectSerializing>

51. MTLManagedObjectSerializing protocol
@interface TGRBook : MTLModel <MTLManagedObjectSerializing>
Specify the entity name

52. MTLManagedObjectSerializing protocol
@interface TGRBook : MTLModel <MTLManagedObjectSerializing>
Specify the entity name
Specify how to map properties to managed
object attributes

53. MTLManagedObjectSerializing protocol
@interface TGRBook : MTLModel <MTLManagedObjectSerializing>
Specify the entity name
Specify how to map properties to managed
object attributes
Specify how to convert a managed object
attribute value to a property key

54. + (NSString *)managedObjectEntityName {
return @"Book";
}
!
+ (NSDictionary *)managedObjectKeysByPropertyKey {
return @{
@"coverURL" : @"coverLink"
};
}
!
+ (NSValueTransformer *)coverURLEntityAttributeTransformer {
return [[NSValueTransformer valueTransformerForName:MTLURLValueTransformerName]
mtl_invertedTransformer];
}

55. MTLManagedObjectAdapter
NSManagedObject *managedBook = [MTLManagedObjectAdapter managedObjectFromModel:book
insertingIntoContext:moc
error:&error];
!
!
!
TGRBook *book = [MTLManagedObjectAdapter modelOfClass:TGRBook.class
fromManagedObject:object
error:&error];

56. A delightful iOS and OS X networking framework
Built on top of Foundation technologies
Easy to use block-based API
Amazing community of developers
Used by some of the most popular apps on iOS
and OSX
https://github.com/AFNetworking/AFNetworking

57. Example: Search books
NSURL *url = [NSURL URLWithString:@"https://itunes.apple.com"];
AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:url];
!
[client getPath:@"search" parameters:@{
@"term" : @"the sandman",
@"entity" : @"ebook"
} success:^(AFHTTPRequestOperation *operation, id JSONResponse) {
NSLog(@"Search results: %@", JSONResponse);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
...
}];

58. JSON Response
{
"resultCount": 50,
"results": [{
"artistId": 3603584,
"artistName": "Neil Gaiman, Sam Kieth & Mike Dringenberg",
"kind": "ebook",
"price": 1.99,
"description": "<p>The first issue of the first volume...",
"currency": "USD",
"genres": ["Graphic Novels", "Books", "Comics & Graphic Novels"],
"genreIds": ["10015", "38", "9026"],
"releaseDate": "2013-05-01T07:00:00Z",
"trackId": 642469670,
"trackName": "Sandman #1",
...

59. Let’s add a Mantle
[client getPath:@"search" parameters:@{
@"term" : @"Neil Gaiman",
@"entity" : @"ebook"
} success:^(AFHTTPRequestOperation *operation, NSDictionary *JSONResponse) {
!
!
NSArray *results = JSONResponse[@"results"];
NSValueTransformer *transformer;
transformer = [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
NSArray *books = [transformer transformedValue:results];
NSLog(@"Books: %@", books);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
...
}];

60. Let’s add a Mantle
[client getPath:@"search" parameters:@{
@"term" : @"Neil Gaiman",
@"entity" : @"ebook"
} success:^(AFHTTPRequestOperation *operation, NSDictionary *JSONResponse) {
!
!
NSArray *results = JSONResponse[@"results"];
NSValueTransformer *transformer;
transformer = [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
NSArray *books = [transformer transformedValue:results];
NSLog(@"Books: %@", books);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
...
}];

61. NSArray *results = JSONResponse[@"results"];
NSValueTransformer *transformer;
transformer = [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
NSArray *books = [transformer transformedValue:results];

62. NSArray *results = JSONResponse[@"results"];
NSValueTransformer *transformer;
transformer = [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
NSArray *books = [transformer transformedValue:results];
Mapping can potentially take time

63. NSArray *results = JSONResponse[@"results"];
NSValueTransformer *transformer;
transformer = [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
NSArray *books = [transformer transformedValue:results];
Mapping can potentially take time
It should be done in a background queue

64. NSArray *results = JSONResponse[@"results"];
NSValueTransformer *transformer;
transformer = [NSValueTransformer mtl_JSONArrayTransformerWithModelClass:TGRBook.class];
NSArray *books = [transformer transformedValue:results];
Mapping can potentially take time
It should be done in a background queue
Boilerplate code again!

65. Overcoat
The perfect accessory for Mantle
Makes it dead simple to use Mantle model
objects with a RESTful client
AFNetworking extension
https://github.com/gonzalezreal/Overcoat

66. Overcoat
OVCRequestOperation
OVCClient
AFJSONRequestOperation
AFHTTPClient
AFHTTPRequestOperation
OVCQuery
OVCSocialClien

67. Overcoat 0.x
OVCQuery *query = [OVCQuery queryWithMethod:OVCQueryMethodGet
path:@"search"
parameters:@{
@"term" : term,
@"entity" : @"ebook"
}
modelClass:TGRBook.class
objectKeyPath:@"results"];
!
[client executeQuery:query
completionBlock:^(OVCRequestOperation *operation, NSArray *books, NSError *error) {
NSLog(@"Books: %@", books);
}];

68. Overcoat 1.0

69. Overcoat 1.0
NSDictionary *parameters = @{
@"term" : term,
@"entity" : @"ebook"
};
!
[client GET:@"search" parameters:parameters resultClass:TGRBook.class resultKeyPath:@"results"
completion:^(AFHTTPRequestOperation *operation, NSArray *books, NSError *error) {
NSLog(@"Books: %@", books);
}];

70. Overcoat 1.0
NSDictionary *parameters = @{
@"term" : term,
@"entity" : @"ebook"
};
!
[client GET:@"search" parameters:parameters resultClass:TGRBook.class resultKeyPath:@"results"
completion:^(AFHTTPRequestOperation *operation, NSArray *books, NSError *error) {
NSLog(@"Books: %@", books);
}];
Coming soon...

71. Overcoat
Server API requests are defined by
OVCQuery objects.
HTTP method, path, parameters, model
class, multipart data, etc.
Maps JSON into model(s)
In a private background queue

72. Overcoat
Pull Requests are welcome!

73. Demo Application
https://github.com/gonzalezreal/ReadingList

74. Thanks!