Core Data: Best Technique to Sort To Many Relationship ordered set

Question

Created Jul ’16

Replies 2

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Say I have a NSManagedObject subclass (Parent) with a to many relationship to another object (call the relationship children).

To display children sorted, I could add a method like this to Parent:

-(NSArray*)sortedChildren
{
NSArray *sorted = [self.children sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"key" ascending:YES]]];

    return sorted;
}

It would not be efficient to resort the children every time I need to access sortedChildren. I suppose I could keep a sorted copy in a property and override all the generated methods to add/insert children make sure the sorted array picks up changes....and nil it out in the didBecomeFault method? Is there a better way to do this? There can potentially be a lot of children so I do want to avoid a method like above.

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Answer 1

taun OP

Jul ’16

How about something like

if (self.children.hasChanges) {

// resort cached sorted array

}

return cachedSortedArrayProperty;

0

Answer 2

Macho Man Randy Savage OP

Jul ’16

Do you mean:

if (self.hasChanges)
{
  //resort
}

Or maybe I should do another fetch request?

0