HobjectiveRecord란

HobjectiveRecord는 Objective-C로 작성된 CoreData용 라이브러리.
오픈소스로 Github에서 자유롭게 이용 가능 합니다.

HobjectiveRecord의 특징

적은 코드량으로 CoreData를 자유롭게 조작 가능하고
특히 백그라운드 처리를 기본으로 하고 있어 UI쓰레드를 블럭하지 않고 사용할 수도 있습니다.

CoreData의 백그라운드 처리에 대한 상세내용은 아래 글들을 참고하세요.

• a-real-guide-to-core-data-concurrency.
• Multi-Context CoreData.

HobjectiveRecord의 이용

이용 준비

1. Github -> HobjectiveRecord에서 다운로드 한후 HobjectiveRecord폴더를 사용할 프로젝트에 복사,
   또는 CocoaPods을 이용 pod 'HobjectiveRecord'
2. 필요한 파일에 #import "HobjectiveRecord.h"를 추가

초기화

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // 우선 CoreData를 이용하기 전에 스토어를 초기화
    [NSPersistentStoreCoordinator setupDefaultStore];
    
    // your code here
    
    return YES;
}
/*
+ (void)setupDefaultStore;
+ (void)setupDefaultStoreWithModelURL:(NSURL *)modelURL storeURL:(NSURL *)storeURL useInMemoryStore:(BOOL)useInMemoryStore;
*/

Basic

기본적으로 모든 처리는 performBlock:안에 기술

[[NSManagedObjectContext defaultContext] performBlock:^{
  // your code here
}];
NSManagedObjectContext *childContext = [[NSManagedObjectContext defaultContext] createChildContext];
[childContext performBlock:^{
  // your code here
}];

Create / Save / Delete

[[NSManagedObjectContext defaultContext] performBlock:^{
    Tweet *tweet = [Tweet create];
    tweet.text = @"I am here";
    [tweet save];
    [tweet delete];
    
    tweet = [Tweet create:@{@"text" : @"hello!!",
                            @"lang" : @"en"} ];
    [tweet saveToStore];
    
    [Tweet deleteAll];
}];
/*
+ (instancetype)create;
+ (instancetype)create:(NSDictionary *)attributes;
+ (void)deleteAll;
+ (void)deleteWithCondition:(id)condition;
- (void)save;
- (void)saveToStore;
- (void)delete;
*/

Finders

[[NSManagedObjectContext defaultContext] performBlock:^{
    NSArray *tweets = [Tweet all];
    
    NSArray *tweetsInEnglish = [Tweet find:@"lang == 'en'"];
    
    User *hmhv = [User first:@"screenName == 'hmhv'"];
    
    NSArray *englishMen = [User find:@{@"lang" : @"en",
                                       @"timeZone" : @"London"
                                       }];
    
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"friendsCount > 100"];
    NSArray *manyFriendsUsers = [User find:predicate];
}];
/*
+ (NSArray *)all;
+ (NSArray *)find:(id)condition;
+ (instancetype)first:(id)condition;
+ (instancetype)firstOrCreate:(NSDictionary *)condition;
*/

Order and Limit

[[NSManagedObjectContext defaultContext] performBlock:^{
    NSArray *sortedUsers = [User allWithOrder:@"name"];
    
    NSArray *allUsers = [User allWithOrder:@"screenName ASC, name DESC"];
    // or
    NSArray *allUsers2 = [User allWithOrder:@"screenName A, name D"];
    // or
    NSArray *allUsers3 = [User allWithOrder:@"screenName, name d"];

    NSArray *manyFriendsUsers = [User find:@"friendsCount > 100" order:@"screenName DESC"];
    
    NSArray *fiveEnglishUsers = [User find:@"lang == 'en'" order:@"screenName ASC" limit:@(5)];
}];
/*
+ (NSArray *)allWithOrder:(NSString *)order;
+ (NSArray *)find:(id)condition order:(NSString *)order;
+ (NSArray *)find:(id)condition limit:(NSNumber *)limit;
+ (NSArray *)find:(id)condition order:(NSString *)order limit:(NSNumber *)limit;
*/

Aggregation

[[NSManagedObjectContext defaultContext] performBlock:^{
    NSUInteger allUserCount = [User count];
    
    NSUInteger englishUserCount = [User countWithCondition:@"lang == 'en'"];
}];
/*
+ (NSUInteger)count;
+ (NSUInteger)countWithCondition:(id)condition;
*/

BatchUpdate

[[NSManagedObjectContext defaultContext] performBlock:^{
    
    [User batchUpdateWithCondition:@"friendsCount > 10" propertiesToUpdate:@{@"friendsCount": @0}];
    
    // update all entities
    [User batchUpdateWithCondition:nil propertiesToUpdate:@{@"friendsCount": @100}];
}];
/*
+ (NSUInteger)batchUpdateWithCondition:(id)condition propertiesToUpdate:(NSDictionary *)propertiesToUpdate;
+ (NSUInteger)batchUpdateWithCondition:(id)condition propertiesToUpdate:(NSDictionary *)propertiesToUpdate inContext:(NSManagedObjectContext *)context;
*/

NSFetchedResultsController

    [[NSManagedObjectContext defaultContext] performBlock:^{
        NSFetchedResultsController *frc = [User createFetchedResultsControllerWithCondition:nil order:@"name" sectionNameKeyPath:nil];
        frc.delegate = self;
        
        NSError *error = nil;
        if ([frc performFetch:&error]) {
            [self reloadData];
        }
    }
}];
/*
+ (NSFetchedResultsController *)createFetchedResultsControllerWithCondition:(id)condition order:(NSString *)order sectionNameKeyPath:(NSString *)sectionNameKeyPath;
*/

Custom ManagedObjectContext

NSManagedObjectContext *childContext = [[NSManagedObjectContext defaultContext] createChildContext];

[childContext performBlock:^{
    User *john = [User createInContext:childContext];
    john.name = @"John";
    [john save];
    
    john = [User first:@"name == 'John'" inContext:childContext];
    
    NSArray *manyFriendsUsers = [User find:@"friendsCount > 100" order:@"screenName DESC" inContext:childContext];
    
    NSArray *allUsers = [User allInContext:childContext];
}];

커스텀 모델, 커스텀 sqlite파일의 이용

NSURL *modelURL = [NSURL defaultModelURL:@"model_name"];
[NSPersistentStoreCoordinator setupDefaultStoreWithModelURL:modelURL storeURL:nil useInMemoryStore:NO];
    
// or
NSURL *storeURL = [NSURL defaultStoreURL:@"file_name.sqlite"];
[NSPersistentStoreCoordinator setupDefaultStoreWithModelURL:nil storeURL:storeURL useInMemoryStore:NO];

맵핑

웹 서비스로 부터의 JSON은 first_name, last_name과 같은 스네이크 케이스인 경우가 많지만,
Objective-C에서는 firstName, lastName과 같은 캐멀 케이스가 주류다.
그래서 스네이크 케이스에서 캐멀 케이스로의 맵핑은 자동으로 됩니다.
그외에 특별한 이름 맵핑이 필요한 경우는 각 모델 클래스에서 mappings을 오버라이드에서 설정가능.

!! Date, Transformable 타입은 맵핑 대상외 입니다. !!

// just override +mappings in your NSManagedObject subclass
#import "User+Mappings.h"

@implementation User (Mappings)

+ (NSDictionary *)mappings
{
    return @{@"description" : @"userDescription",
             @"name" : @"fullName"};
}
  // first_name => firstName 은 자동으로 맵핑됨

@end
/*
+ (NSDictionary *)mappings
+ (BOOL)useFindOrCreate
+ (BOOL)returnsObjectsAsFaults
+ (NSArray *)relationshipKeyPathsForPrefetching
*/

테스트

HobjectiveRecord은 메모리내 스토어를 설정가능합니다. 테스트 이용에 편리합니다.

[NSPersistentStoreCoordinator setupDefaultStoreWithModelURL:nil storeURL:nil useInMemoryStore:YES];