Instance Method

willChange:valuesAtIndexes:forKey:

Informs the observed object that the specified change is about to be executed at given indexes for a specified ordered to-many relationship.

Declaration

- (void)willChange:(NSKeyValueChange)changeKind valuesAtIndexes:(NSIndexSet *)indexes forKey:(NSString *)key;

Parameters

change

The type of change that is about to be made.

indexes

The indexes of the to-many relationship that will be affected by the change.

key

The name of a property that is an ordered to-many relationship.

Discussion

Use this method when implementing key-value-observing compliance manually.

Special Considerations

You rarely need to override this method in subclasses, but if you do, be sure to call super.

See Also

Notifying Observers of Changes

- willChangeValueForKey:

Informs the observed object that the value of a given property is about to change.

- didChangeValueForKey:

Informs the observed object that the value of a given property has changed.

- didChange:valuesAtIndexes:forKey:

Informs the observed object that the specified change has occurred on the indexes for a specified ordered to-many relationship.

- willChangeValueForKey:withSetMutation:usingObjects:

Informs the observed object that the specified change is about to be made to a specified unordered to-many relationship.

- didChangeValueForKey:withSetMutation:usingObjects:

Informs the observed object that the specified change was made to a specified unordered to-many relationship.