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Forked from rojotek/DataManager.h
Created August 7, 2012 15:43
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Core Data singleton manager class capable of being run from a static library - updated for ARC.
// DataManager.h
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
extern NSString * const DataManagerDidSaveNotification;
extern NSString * const DataManagerDidSaveFailedNotification;
@interface DataManager : NSObject {
}
@property (nonatomic, readonly, retain) NSManagedObjectModel *objectModel;
@property (nonatomic, readonly, retain) NSManagedObjectContext *mainObjectContext;
@property (nonatomic, readonly, retain) NSPersistentStoreCoordinator *persistentStoreCoordinator;
+ (DataManager*)sharedInstance;
- (BOOL)save;
- (NSManagedObjectContext*)managedObjectContext;
@end
// DataManager.m
#import "DataManager.h"
NSString * const DataManagerDidSaveNotification = @"DataManagerDidSaveNotification";
NSString * const DataManagerDidSaveFailedNotification = @"DataManagerDidSaveFailedNotification";
@interface DataManager ()
- (NSString*)sharedDocumentsPath;
@end
@implementation DataManager
@synthesize persistentStoreCoordinator = _persistentStoreCoordinator;
@synthesize mainObjectContext = _mainObjectContext;
@synthesize objectModel = _objectModel;
NSString * const kDataManagerBundleName = @"MyApp";
NSString * const kDataManagerModelName = @"MyApp";
NSString * const kDataManagerSQLiteName = @"MyApp.sqlite";
+ (DataManager*)sharedInstance {
static dispatch_once_t pred;
static DataManager *sharedInstance = nil;
dispatch_once(&pred, ^{ sharedInstance = [[self alloc] init]; });
return sharedInstance;
}
- (void)dealloc {
[self save];
}
- (NSManagedObjectModel*)objectModel {
if (_objectModel)
return _objectModel;
NSBundle *bundle = [NSBundle mainBundle];
if (kDataManagerBundleName) {
NSString *bundlePath = [[NSBundle mainBundle] pathForResource:kDataManagerBundleName ofType:@"bundle"];
bundle = [NSBundle bundleWithPath:bundlePath];
}
NSString *modelPath = [bundle pathForResource:kDataManagerModelName ofType:@"momd"];
_objectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:[NSURL fileURLWithPath:modelPath]];
return _objectModel;
}
- (NSPersistentStoreCoordinator*)persistentStoreCoordinator {
if (_persistentStoreCoordinator)
return _persistentStoreCoordinator;
// Get the paths to the SQLite file
NSString *storePath = [[self sharedDocumentsPath] stringByAppendingPathComponent:kDataManagerSQLiteName];
NSURL *storeURL = [NSURL fileURLWithPath:storePath];
// Define the Core Data version migration options
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption,
nil];
// Attempt to load the persistent store
NSError *error = nil;
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:self.objectModel];
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:storeURL
options:options
error:&error]) {
/*
TODO: Replace this implementation with code to handle the error appropriately.
...
If you encounter schema incompatibility errors during development, you can reduce their frequency by:
* Simply deleting the existing store:
[[NSFileManager defaultManager] removeItemAtURL:storeURL error:nil]
* Performing automatic lightweight migration by passing the following dictionary as the options parameter:
[NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
*/
NSLog(@"Fatal error while creating persistent store: %@", error);
abort();
}
return _persistentStoreCoordinator;
}
- (NSManagedObjectContext*)mainObjectContext {
if (_mainObjectContext)
return _mainObjectContext;
// Create the main context only on the main thread
if (![NSThread isMainThread]) {
[self performSelectorOnMainThread:@selector(mainObjectContext)
withObject:nil
waitUntilDone:YES];
return _mainObjectContext;
}
_mainObjectContext = [[NSManagedObjectContext alloc] init];
[_mainObjectContext setPersistentStoreCoordinator:self.persistentStoreCoordinator];
return _mainObjectContext;
}
- (BOOL)save {
if (![self.mainObjectContext hasChanges])
return YES;
NSError *error = nil;
if (![self.mainObjectContext save:&error]) {
NSLog(@"Error while saving: %@\n%@", [error localizedDescription], [error userInfo]);
[[NSNotificationCenter defaultCenter] postNotificationName:DataManagerDidSaveFailedNotification
object:error];
return NO;
}
[[NSNotificationCenter defaultCenter] postNotificationName:DataManagerDidSaveNotification object:nil];
return YES;
}
- (NSString*)sharedDocumentsPath {
static NSString *SharedDocumentsPath = nil;
if (SharedDocumentsPath)
return SharedDocumentsPath;
// Compose a path to the <Library>/Database directory
NSString *libraryPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) objectAtIndex:0];
SharedDocumentsPath = [libraryPath stringByAppendingPathComponent:@"Database"];
// Ensure the database directory exists
NSFileManager *manager = [NSFileManager defaultManager];
BOOL isDirectory;
if (![manager fileExistsAtPath:SharedDocumentsPath isDirectory:&isDirectory] || !isDirectory) {
NSError *error = nil;
NSDictionary *attr = [NSDictionary dictionaryWithObject:NSFileProtectionComplete
forKey:NSFileProtectionKey];
[manager createDirectoryAtPath:SharedDocumentsPath
withIntermediateDirectories:YES
attributes:attr
error:&error];
if (error)
NSLog(@"Error creating directory path: %@", [error localizedDescription]);
}
return SharedDocumentsPath;
}
- (NSManagedObjectContext*)managedObjectContext {
NSManagedObjectContext *ctx = [[NSManagedObjectContext alloc] init];
[ctx setPersistentStoreCoordinator:self.persistentStoreCoordinator];
return ctx;
}
@end
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