CODEWITHSUNDEEP
iphoneobjective-cioscocoa-touchcore-data
freestyler
freestyler

Reputation: 5444

How to fix ‘NSObjectInaccessibleException’ fetch request cannot respond to -entity until used by an NSManagedObjectContext'

The code works fine in iOS5+:

NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"FooBar"];
request.sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"ident"
                                                                                 ascending:NO
                                                                                  selector:@selector(compare:)]];
request.predicate = [NSPredicate predicateWithFormat:@"xxx = %@", @"yyy"];

self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request
                                                                    managedObjectContext:model.managedObjectContext
                                                                      sectionNameKeyPath:nil
                                                                               cacheName:nil];

But in iOS 4, I got the following error:

'NSObjectInaccessibleException', reason: 'This fetch request (0x70d4700) 
was created with a string name (FooBar), and cannot respond to -entity 
until used by an NSManagedObjectContext'

2012-11-08 12:12:18.093 hello[1566:11d03] *** Terminating app due to uncaught
exception 'NSObjectInaccessibleException', reason: 'This fetch request 
(0x70d4700) was created with a string name (FooBar), and cannot respond 
to -entity until used by an NSManagedObjectContext'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x012405a9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x0104a313 objc_exception_throw + 44
    2   CoreData                            0x000be68f -[NSFetchRequest entity] + 159
    3   CoreData                            0x0019f7fb -[NSFetchedResultsController initWithFetchRequest:managedObjectContext:sectionNameKeyPath:cacheName:] + 763
    ...

How can I resolve this error?

Upvotes: 1

Views: 601

Answers (2)

Daij-Djan
Daij-Djan

Reputation: 50089

the problem is that the NSFetchRequest has no context to get the object from... you always need a specific context to get an entityDescription from. In ios5 the getting of entityDescription is nicely hidden and delayed till you execute the fetch :) In for its not

the header is wrong btw. it says its all good for ios4:

+ (NSFetchRequest*)fetchRequestWithEntityName:(NSString*)entityName NS_AVAILABLE(10_7, 4_0);

Id file a bug. Anyways@Martin R is correct :)

Upvotes: 0

Martin R
Martin R

Reputation: 539685

fetchRequestWithEntityName: is available only in iOS 5 and later.

On iOS 4, you have to create a NSEntityDescription first:

NSEntityDescription *fooBarEntity = [NSEntityDescription entityForName:@"FooBar" inManagedObjectContext:model.managedObjectContext];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:fooBarEntity];

Upvotes: 7

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