Core Data fetching deleted objects - ios

Question

Short version of my problem: I'm deleting an object and after I do a fetch that returns the previously deleted object.
I'm following this architecture:
SyncService -> Persistence Service -> NSManagedObject
All my classes in Persistence Service layer are children of the following class:
# PersistenceService.h
#import <Foundation/Foundation.h>
#interface PersistenceService : NSObject
#property (nonatomic, retain) NSManagedObjectContext *context;
-(instancetype) init;
-(void) saveContext;
#end
# PersistenceService.m
#implementation PersistenceService
-(instancetype) init {
self = [super init];
if (self) {
self.context = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
self.context.parentContext = [DataManager sharedInstance].managedObjectContext;
}
return self;
}
-(void) saveContext {
NSManagedObjectContext *context = self.context.parentContext;
[self.context performBlock:^{
NSError *error;
[self.context save:&error];
[context performBlock:^{
NSError *error;
[context save:&error];
[context.parentContext performBlock:^{
NSError *error;
[context.parentContext save:&error];
}];
}];
}];
}
#end
Before the deletion, I fetch the object in my main context:
# Synchronizer.m
-(void) synchronize {
NSArray *pseudoLeads = [[[PseudoLeadPersistenceService alloc] init] getAllParentPseudoLeads];
if (pseudoLeads) {
PseudoLeadDAO *pseudoLead = [pseudoLeads objectAtIndex:0];
if ([pseudoLead.type isEqualToNumber:[NSNumber numberWithInt:Capture]]) {
CaptureSyncService *service = [[CaptureSyncService alloc] initWithDelegate:self andPseudoLead:pseudoLead];
[service executeRequest];
} else {
HotleadSyncService *service = [[HotleadSyncService alloc] initWithDelegate:self andPseudoLead:pseudoLead];
[service executeRequest];
}
}
}
.
# PseudoLeadPersistenceService.m
-(NSArray *) getAllParentPseudoLeads {
return [PseudoLeadDAO findAllParentPseudoLeadsInContext:self.context.parentContext];
}
And here I fetch and actually delete the object in my subcontext:
# PseudoLeadPersistenceService.m
-(void) deletePseudoLeadById:(NSNumber *)pseudoLeadId andEventId:(NSNumber *)eventId {
PseudoLeadDAO *pseudoLeadDAO = [PseudoLeadDAO findPseudoLeadById:pseudoLeadId andEventId:eventId inContext:self.context];
[self.context deleteObject:pseudoLeadDAO];
[self saveContext];
}
Then the -(void) synchronize is called again and the deleted object shows up again as a fault. At this point, I can fetch as many times as I want and it will be returned. It only goes away when it comes to -(void) deletePseudoLeadById:(NSNumber *)pseudoLeadId andEventId:(NSNumber *)eventId method again and the fault is fired.
I'll appreciate any help given. Thanks!

Answer 1

The problem was concurrency. The thread started to save the context wasn't getting done before the next fetch.
I solved the problem by using performBlockAndWait:
# PersistenceService.m
-(void) saveContextAndWait {
NSManagedObjectContext *context = self.context.parentContext;
[self.context performBlockAndWait:^{
NSError *error;
[self.context save:&error];
[context performBlockAndWait:^{
NSError *error;
[context save:&error];
[context.parentContext performBlockAndWait:^{
NSError *error;
[context.parentContext save:&error];
}];
}];
}];
}
.
# PseudoLeadPersistenceService.m
-(void) deletePseudoLeadById:(NSNumber *)pseudoLeadId andEventId:(NSNumber *)eventId {
PseudoLeadDAO *pseudoLeadDAO = [PseudoLeadDAO findPseudoLeadById:pseudoLeadId andEventId:eventId inContext:self.context];
[self.context deleteObject:pseudoLeadDAO];
[self saveContextAndWait];
}