xcode Core Data edit value for key issue - objective-c

Question

Got a problem here...
My BOOL gets edited and I get success at the last NSLog, but when I close the ViewController and then go in again (update the table), the BOOL go back to the first value. That will say - something is wrong in my [context save:&error]; function.
Any ideas?
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
for (int i=0; i<[self tableView:tableView numberOfRowsInSection:0]; i++) {
AccountCell *cell = (AccountCell *)[tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:i inSection:0]];
[cell setSelected:(i==indexPath.row) animated:NO];
NSManagedObject *user = [arr objectAtIndex:indexPath.row];
[user setValue:[NSNumber numberWithBool:(i==indexPath.row)] forKey:#"active"];
NSLog(#"Index: %i, Active State: %#", i,[user valueForKey:#"active"]);
NSError *error;
if (![context save:&error]) {
NSLog(#"Saving changes to context failed: %#", error);
} else {
// The changes have been persisted.
NSLog(#"Saved data success");
}
}
}

Answer 1

Some suggestions:
It would make much more sense to put the save statement outside the for loop.
You need to check if
your managed object context is valid (non-nil)
the context of the objects of your mysterious arr array is the same as the context you are saving
the "active" property (including spelling) is correctly configured in your model and the managed object (maybe you want to subclass for more clarity rather than relying on KVC).
there is something in the error variable
I also think there are some other design flaws. For example, you are getting cells and setting their selected state even though they might not even be visible. IMO, you should do this in cellForRowAtIndexPath, based on the state of the underlying managed object.
As for deselecting all other users in the same section you are right that a loop is probably inevitable. But I suppose it would be more efficient to fetch all users in a section at once and then loop through them to set the "active" property as desired.