我正在为较大的iOS应用程序编写Core Data ContextManager。 ContextManager提供了一个NSManagedContext,当其他ContextManagers将其NSMangedContext保存到持久数据存储区时,它将自动更新。核心数据mergeChangesFromContextDidSaveNotification无效
我有一个单元测试(TestContextManager),创建两个上下文,将一个对象添加到一个,并测试以查看该对象是否出现在另一个上下文中。它没有。 为什么最后一次测试失败?
以下是ContextManager的代码和失败的单元测试。单元测试中的最后一个断言失败。每隔一个断言通行证。如您所见,ContextManager依赖从其他ContextManager获取更改通知并使用mergeChangesFromContextDidSaveNotification
来更新自身。注意一切都发生在同一个线程上进行这个测试。
我知道NSManagedObjectContextDidSaveNotification正在发送和正确接收。我知道NSManagedObjectContextDidSaveNotification在其userInfo字典中有正确的数据。
我也运行这个单元测试作为应用程序测试在实际的设备上使用SQLite持久性存储 - 相同的断言失败。
在此先感谢!
ContextManager:
#import "ContextManager.h"
@implementation ContextManager
@synthesize context;
#pragma mark - Custom code
- (void)save {
NSError *error = nil;
if (self.context != nil) {
if ([self.context hasChanges] && ![self.context save:&error]) {
NSAssert1(FALSE, @"Unable to save the managed object context. UserInfo:\n%@", [error userInfo]);
}
}
return;
}
- (void)mergeChanges:(NSNotification *)notification {
if (notification.object != self.context) {
[self.context mergeChangesFromContextDidSaveNotification:notification];
}
return;
}
#pragma mark - Overridden NSObject methods
#pragma mark Creating, copying, and deallocating object
- (id)initWithPersistentStoreCoordinator:(NSPersistentStoreCoordinator *)persistentStoreCoordinator {
self = [super init];
if (self) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(mergeChanges:) name:NSManagedObjectContextDidSaveNotification object:nil];
self.context = [[[NSManagedObjectContext alloc] init] autorelease];
[self.context setPersistentStoreCoordinator:persistentStoreCoordinator];
}
return self;
}
- (void)dealloc {
[context release];
[super dealloc];
return;
}
@end
TestContextManager来:
#import "TestContextManager.h"
#import "ContextManager.h"
#import "CoreDataManager.h"
#define TEST_MANAGED_OBJECT @"AManagedObject"
@implementation TestContextManager
- (void)testContextManager {
CoreDataManager *coreDataManager = [[CoreDataManager alloc] init];
coreDataManager.storeType = NSInMemoryStoreType;
ContextManager *contextManagerA = [coreDataManager provideContextManager];
if (!contextManagerA) STFail(@"CoreDataManager did not provide a context manager.");
NSManagedObjectContext *contextA = contextManagerA.context;
if (!contextA) STFail(@"ContextManager did not provide a managed object context.");
// setA1 has 0 objects (or whatever is initially there).
NSSet *setA1 = [contextManagerA.context registeredObjects];
[NSEntityDescription insertNewObjectForEntityForName:TEST_MANAGED_OBJECT inManagedObjectContext:contextManagerA.context];
// setA2 has 1 object.
NSSet *setA2 = [contextManagerA.context registeredObjects];
STAssertTrue([setA2 count] == [setA1 count]+1, @"Context provided by ContextManager is not accepting new objects.");
[contextManagerA save];
ContextManager *contextManagerB = [coreDataManager provideContextManager];
[NSEntityDescription insertNewObjectForEntityForName:TEST_MANAGED_OBJECT inManagedObjectContext:contextManagerB.context];
[contextManagerB save];
NSSet *setA3 = [contextManagerA.context registeredObjects];
// setA3 should have 2 objects <=== THIS TEST FAILS
STAssertTrue([setA3 count] == [setA1 count]+2, @"Context is not updating new objects.");
[coreDataManager release];
return;
}
@end
是。这是在ContextManager的initWithPersistentStoreCoordinator:方法中完成的。我还使用日志记录来验证ContextManager正在发送和接收通知。 – Erik 2011-04-06 23:30:19
哦,等一下,我刚刚注意到了一些东西。问题不在于测试中的合并。您对setA1&setA2的赋值导致指向相同的对象。您应该为每个对象创建一个注册对象的副本,或者在添加一个新对象之前获取每个对象的数量。 – 2011-04-06 23:38:21
我认为NSManagedContext发送并自动释放NSSet作为registrationObjects的返回值。但是,以防万一,我已经更新了我的代码,下面我添加了。不幸的是,测试仍然失败...... – Erik 2011-04-06 23:53:14