Inconsistency in Saving/Fetching Data in Core Data - ios

Question

My first post here, getting straight to the point.
I'm facing a problem and I'm not sure whether is with saving of data or fetching it.
Here are my codes where I tried to save the data in my Entity, "Sequence". The entity consists of 2 attributes "seqForWk1CD" & "seqForWk2CD".
AppDelegate *delegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [delegate managedObjectContext];
SequenceMO *seqEntity = [NSEntityDescription
insertNewObjectForEntityForName:#"Sequence"
inManagedObjectContext:context];
// some other code
seqEntity.seqForWk1CD = arrForWk1;
seqEntity.seqForWk2CD = arrForWk2;
NSLog(#"%#", arrForWk1);
NSLog(#"%#", arrForWk2);
NSError *error = nil;
if (context != nil) {
if ([context hasChanges] && ![context save:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
When printed, the arrays will always display the contents of the array.
This is where I try to fetch the data.
AppDelegate *delegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [delegate managedObjectContext];
NSFetchRequest *request = [[NSFetchRequest alloc]init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Sequence" inManagedObjectContext:context];
[request setEntity:entity];
NSError *error;
if(![context save:&error]){
NSLog(#"Error fetching. %# %#", error, [error localizedDescription]);
}
NSUInteger count = [context countForFetchRequest:request error:&error];
if(count != 0){
NSArray *fetchObj = [context executeFetchRequest:request error:&error];
NSManagedObject *sequence = (NSManagedObject *)[fetchObj objectAtIndex:0];
NSLog(#"1 - %#", sequence);
arrForWk1 = [sequence valueForKey:#"seqForWk1CD"];
NSLog(#"%#", arrForWk1);
arrForWk2 = [sequence valueForKey:#"seqForWk2CD"];
NSLog(#"%#", arrForWk2);
}
The problem comes when I restart the application. The arrays either show (null) for both arrays or it shows the contents of both of the arrays. The if statement for if(![context save:&error]) never gets triggered. Subclasses of NSManagedObject for the entity has already been added.I've also tried declaring the AppDelegate in #interface and forced to save the context immediately by doing [delegate saveContext];.Here is the method where the saving happens. "check" is initialized to 0 at the viewDidLoad method. Both "arrForWk1" & "arrForWk2" are declared at #interface.
- (IBAction)randomizeSequence:(UIButton *)sender {
NSMutableArray *storeArray = [[NSMutableArray alloc] init];
AppDelegate *delegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [delegate managedObjectContext];
SequenceMO *seqEntity = [NSEntityDescription insertNewObjectForEntityForName:#"Sequence" inManagedObjectContext:context];
BOOL record = NO;
int x;
for (int i=0; [storeArray count] < 9; i++) //Loop for generate different random values
{
x = 1 + arc4random() % 9;//generating random number
if(i==0)//for first time
{
[storeArray addObject:[NSNumber numberWithInt:x]];
}
else
{
for (int j=0; j<= [storeArray count]-1; j++)
{
if (x ==[[storeArray objectAtIndex:j] intValue])
record = YES;
}
if (record == YES)
{
record = NO;
}
else
{
[storeArray addObject:[NSNumber numberWithInt:x]];
}
}
}
check++;
if(check == 1 ) {
arrForWk1 = storeArray;
[self.wk1Seq reloadData];
}
else if(check == 2) {
arrForWk2 = storeArray;
seqEntity.seqForWk1CD = arrForWk1;
seqEntity.seqForWk2CD = arrForWk2;
NSError *error = nil;
if (context != nil) {
if ([context hasChanges] && ![context save:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
[self.wk2Seq reloadData];
}
Just to add on, the arrays are of data type NSMutableArray and I'm trying to store them into attributes of type "Transformable".

Answer 1

After researching around I managed to solve the problem. I'm not sure how it actually works but I solved it by rearranging the code when I'm trying to fetch the data.
AppDelegate *delegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [delegate managedObjectContext];
NSEntityDescription *descriptor = [NSEntityDescription entityForName:#"Sequence" inManagedObjectContext:context];
NSFetchRequest *request = [[NSFetchRequest alloc]init];
request.entity = descriptor;
NSError *error;
NSArray *fetchObj = [context executeFetchRequest:request error:&error];
if(fetchObj == nil) {
NSLog(#"Error occured when trying to fetch.");
}
else {
if(fetchObj.count == 0) {
NSLog(#"No objects saved");
else {
NSManagedObject *sequence = (NSManagedObject *)[fetchObj objectAtIndex:0];
NSLog(#"1 - %#", sequence);
arrForWk1 = [sequence valueForKey:#"seqForWk1CD"];
NSLog(#"%#", arrForWk1);
arrForWk2 = [sequence valueForKey:#"seqForWk2CD"];
NSLog(#"%#", arrForWk2);
NSLog(#"2 - %#", sequence);
}
I've tried also tried 2 ways of saving the data. In the if statement where I tried to save the data, I converted the NSMutableArrays to NSArrays.
else if(check == 2) {
test2 = storeArray;
NSManagedObjectContext *context = [delegate managedObjectContext];
SequenceMO *seqEntity = [NSEntityDescription insertNewObjectForEntityForName:#"Sequence" inManagedObjectContext:context];
NSArray *tArr = [arrForWk1 copy];
NSArray *tArr2 = [arrForWk2 copy];
seqEntity.seqForWk1CD = tArr;
seqEntity.seqForWk2CD = tArr2;
NSError *error = nil;
if (context != nil) {
if ([context hasChanges] && ![context save:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
The second way I tried is by using an answer from Core Data not saving changes to Transformable property
id temp = [seqEntity seqForWk1CD];
id temp2 = [seqEntity seqForWk2CD];
temp = arrForWk1;
temp2 = arrForWk2;
[seqEntity setSeqForWk1CD:temp];
[seqEntity setSeqForWk2CD:temp2];
Apparently it worked somehow.