CODEWITHSUNDEEP
ioscore-datansmanagedobjectcontextnsfetchrequest
wolfrevo
wolfrevo

Reputation: 2032

Not able to handle executeFetchRequest error

My fetch request works fine and I get my fetched objects without any problems. What I want to do, is handle the error in case the entity doesn't exist. The problem is, I can't handle the error because the app crashes when I call executeFetechRequest: error: without any warnings.

My fetch looks like:

NSManagedObjectContext *context = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];

NSFetchRequest *request = [[NSFetchRequest alloc] init];
request.entity = [NSEntityDescription entityForName:@"Info" inManagedObjectContext:context];
request.sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"infoID" ascending:YES]];
[request setReturnsObjectsAsFaults:NO];

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"infoID like %@",[a substringFromIndex:13]];
request.predicate = predicate;
request.fetchBatchSize = 1;

NSError *error = nil;

NSArray *results = [context executeFetchRequest:request error:&error];

if (error == nil) {
    ...
}
else {
    //handle error
}

As I said, there's no problem as long as the entity exists, but I want to handle the error if it doesn't exist. Any idea? Cheers

Upvotes: 1

Views: 2096

Answers (1)

Leonardo
Leonardo

Reputation: 9857

You could ask the model if such entity is present:

    NSArray *entities = managedObjectModel.entities;
    BOOL canExecute=NO;
    for(NSEntityDescription *ed in entities) {
       // check if entity name is equal to the one you are looking for
       if(found) {
          canExecute=YES;
          break;
       }
    }

   if(canExecute) {
     // execute your request and all the rest...
   } else {
     NSLog(@"Entity description not found");
   }

if doesn't exist you don't execute the fetch reuest

Upvotes: 1

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