我有一个看起来像这样的核心数据模型。
在一个表格视图中，我加载了我所有的约会。在我的UILabel内部，我custom cell将约会位置名称设置如下。
NSString *info = appointment.location.label_vrij;
起初一切正常，但当我将更多约会加载到我的database. 所有的信息字符串都去NULL。经过一些调试后，我注意到它也appointment.location返回了NULL.
这就是我的 NSFetchRequest 的样子
RKManagedObjectStore *store = [[SanMaxDataModel sharedDataModel] objectStore];
NSManagedObjectContext *context = store.mainQueueManagedObjectContext;
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"Appointment"];
NSString *relationshipKeyPath = @"location"; // Set this to the name of the relationship on "A" that points to the "B" objects;
NSArray *keyPaths = [NSArray arrayWithObject:relationshipKeyPath];
[fetchRequest setRelationshipKeyPathsForPrefetching:keyPaths];
NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:@"dateStart" ascending:YES];
fetchRequest.sortDescriptors = @[descriptor];
NSPredicate *predicate = [NSPredicate predicateWithFormat:
@"tijd_dag = %@",strDate];
[fetchRequest setPredicate:predicate];
NSArray *matches = [context executeFetchRequest:fetchRequest error:nil];
appointments = [matches mutableCopy];
所以我认为我的关系只是搞砸了？
编辑
我正在使用 Restkit 将我的约会映射到我的核心数据库中。从下面的评论中，我决定关闭 Appointment 实体中 location 属性的选项标志。因为约会应该总是有一个位置。
现在当我加载的第一天。一切正常。但是当我第二天尝试加载时，我得到了错误：The operation couldn\U2019t be completed. (Cocoa error 1570.) 现在当我查看详细的错误时
DetailedError: {
NSLocalizedDescription = "The operation couldn\U2019t be completed. (Cocoa error 1570.)";
NSValidationErrorKey = location;
NSValidationErrorObject = "<Appointment: 0x864e2f0> (entity: Appointment; id: 0x9272c70 <x-coredata://9692683D-3077-4362-9253-652AC5B36444/Appointment/p9> ; data: {\n autouur = 1;\n breekuur = 0;\n data1 = \"\";\n data2 = \"\";\n data3 = \"\";\n data4 = \"\";\n data5 = \"\";\n data6 = \"\";\n data7 = \"\";\n data8 = \"\";\n data9 = \"\";\n dateStart = \"2013-10-23 09:00:00 +0000\";\n dateStop = \"2013-10-23 09:30:00 +0000\";\n duration = 30;\n email = \"\";\n entryID = 774294984959;\n info = \"\";\n \"is_blocked\" = 0;\n \"is_except\" = 0;\n \"is_free\" = 1;\n \"is_moved\" = 0;\n \"is_vert\" = 0;\n locatieID = 773150;\n location = nil;\n multiID = nil;\n serverEntryID = 774294984959;\n serverLocatieID = 773150;\n sms = \"\";\n \"tijd_dag\" = 20131023;\n \"tijd_uur\" = 900;\n})";
}
这就是我在核心数据中加载 JSON 的方式
-(void)getAppointmentsForDate:(NSString *)date forUserID:(NSString *)userID{
API *api = [API new];
RKManagedObjectStore *store = [[SanMaxDataModel sharedDataModel] objectStore];
NSLog(@"store is %@",store);
NSManagedObjectContext *context = store.mainQueueManagedObjectContext;
RKObjectManager *objectManager = [api mapAppointments];
NSString *urlString = [NSString stringWithFormat:@"/doctor/1.0/json/nl/appointments/get-by-date/apikey/%@?uid=%@&date=%@",APIKey,userID,date];
// NSString *urlString = [NSString stringWithFormat:@"/doctor/1.0/json/nl/appointments/get-by-date/apikey/%@?uid=77382&date=%@",APIKey,date];
NSURLRequest *request = [objectManager requestWithObject:nil method:RKRequestMethodGET path:urlString parameters:nil];
RKManagedObjectRequestOperation *operation = [objectManager managedObjectRequestOperationWithRequest:request managedObjectContext:context success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
NSLog(@"TILL HERE IN METHOD");
NSError *error = nil;
[[NSNotificationCenter defaultCenter] postNotificationName:@"appointmentsLoaded" object:self];
[[SanMaxDataModel sharedDataModel] saveToPersistentStoreAsync:&error];
} failure:^(RKObjectRequestOperation *operation, NSError *error) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alert show];
NSLog(@"Hit error: %@", error);
}];
[objectManager enqueueObjectRequestOperation:operation];
}