Fetched Property works in iOS5 but not iOS6 - ios

Question

I am having a serious issue within my CoreData database. I have created a One To Many relationship between 2 tables and added a Fetched Property on the Table containing all unique values. All code works as expected within iOS 5 but in iOS 6 I receive the following errror:
2013-02-08 15:15:49.382 ArdsBoroughCouncil[16152:c07] * Terminating
app due to uncaught exception 'NSUnknownKeyException', reason:
'[<_NSObjectID_48_0 0xb25c3b0> valueForUndefinedKey:]: this class is
not key value coding-compliant for the key tour_id.'
* First throw call stack: (0x31c7012 0x24a3e7e 0x324ffb1 0x1c445ed 0x1bb08db 0x1bb088d 0x1bceb17 0x1bfe746 0x21b74bb 0x21b7176 0x21b6e44
0x21b66f4 0x21b2d63 0x21b2a82 0x21b2850 0x21b2625 0x21b1e07 0x21b18f4
0x21b0a6d 0x21ae9c9 0x2201276 0x227b155 0x2201071 0x2880014 0x286fd5f
0x286faa3 0x220103b 0x2200e9e 0x21ae9c9 0x2209dfa 0x22375cf 0x2237a03
0x59de1 0x11c2753 0x11c2a7b 0x11d0590 0x11d85bd 0x11d8eab 0x11d94a3
0x11d9098 0x1534da3 0x1526ad9 0x1526b54 0x24b7705 0x10e2920 0x10e28b8
0x11a3671 0x11a3bcf 0x11a2d38 0x111233f 0x1112552 0x10f03aa 0x10e1cf8
0x34b3df9 0x34b3ad0 0x313cbf5 0x313c962 0x316dbb6 0x316cf44 0x316ce1b
0x34b27e3 0x34b2668 0x10df65c 0x291d 0x2845) libc++abi.dylib:
terminate called throwing an exception
The predicate defined for the Fetched Property is:
($FETCH_SOURCE.tour_id == tour_id) AND ($FETCH_SOURCE != SELF)
I have defined the array to return all receive all values within my Tour class.
Are you aware of any issues with Fetched Properties wihtin iOS 6 ? As I cannot understand this works with no issue in iOS 5 but fails in iOS6.
Please see all other related code below:
The code below is how I am retrieving all records:
- (void)loadRecordsFromCoreData {
[self.managedObjectContext performBlockAndWait:^{
[self.managedObjectContext reset];
NSError *error = nil;
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:NSStringFromClass([Tour class]) inManagedObjectContext:self.managedObjectContext];
[request setEntity:entityDescription];
[request setResultType:NSManagedObjectResultType];
[request setSortDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:#"tour_id" ascending:YES]]];
self.tours = [self.managedObjectContext executeFetchRequest:request error:&error];
}];
The code below shoes the NSManagedObjects I have defined:
-- Tour
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
#class TourDetail;
#interface Tour : NSManagedObject
#property (nonatomic, retain) NSNumber * tour_id;
#property (nonatomic, retain) NSString * background_url;
#property (nonatomic, retain) NSString * summary;
#property (nonatomic, retain) NSString * title;
#property (nonatomic, retain) NSSet *tourdetails_tour;
#property (nonatomic, retain) NSArray *tourDetails;
#end
#interface Tour (CoreDataGeneratedAccessors)
- (void)addTourdetails_tourObject:(TourDetail *)value;
- (void)removeTourdetails_tourObject:(TourDetail *)value;
- (void)addTourdetails_tour:(NSSet *)values;
- (void)removeTourdetails_tour:(NSSet *)values;
#end
}
#import "Tour.h"
#import "TourDetail.h"
#implementation Tour
#dynamic tour_id;
#dynamic background_url;
#dynamic summary;
#dynamic title;
#dynamic tourdetails_tour;
#dynamic tourDetails;
#end
-- Tour Detail
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
#class Tour;
#interface TourDetail : NSManagedObject
#property (nonatomic, retain) NSNumber * id;
#property (nonatomic, retain) NSNumber * tour_id;
#property (nonatomic, retain) NSNumber * lattitude;
#property (nonatomic, retain) NSNumber * longitude;
#property (nonatomic, retain) NSString * audiofile;
#property (nonatomic, retain) NSString * detail;
#property (nonatomic, retain) NSString * title;
#property (nonatomic, retain) Tour *tour_tourdetails;
#end
#import "TourDetail.h"
#import "Tour.h"
#implementation TourDetail
#dynamic id;
#dynamic tour_id;
#dynamic lattitude;
#dynamic longitude;
#dynamic audiofile;
#dynamic detail;
#dynamic title;
#dynamic tour_tourdetails;
#end
Any advise you can offer would be greatly appreciated :) As well as any examples you may have as to how best to define fetched properties ?
Thanks,
Michael

Answer 1

The code your using here is not clean
- (void)loadRecordsFromCoreData {
[self.managedObjectContext performBlockAndWait:^{
[self.managedObjectContext reset];
NSError *error = nil;
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:NSStringFromClass([Tour class]) inManagedObjectContext:self.managedObjectContext];
[request setEntity:entityDescription];
[request setResultType:NSManagedObjectResultType];
[request setSortDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:#"tour_id" ascending:YES]]];
self.tours = [self.managedObjectContext executeFetchRequest:request error:&error];
}];
In fact, it is a little confusing.
Your calling a method, that calls a managed object context, which further calls itself within a synchronous block, which resets itself for no reason, which sets a property 'self.tours' outside of the block. All very odd. Can you explain why you are doing this?
Try this instead.
+(void)loadRecordsWithCompletion:(void(^)(NSArray *records, NSError *error))completion {
NSManagedObjectContext *context; //Your context
NSError *error;
NSSortDescriptor *sortDesc = [NSSortDescriptor sortDescriptorWithKey:#"attribute" ascending:YES];
NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:#"EntityName"];
[request setSortDescriptors:#[sortDesc]];
NSArray *records = [context executeFetchRequest:request
error:&error];
completion(records, error);
}