Debounce method for Objective C

NSObject+Debounce.h

@interface NSObject (Debounce)

- (void)debounce:(SEL)action delay:(NSTimeInterval)delay;

@end

NSObject+Debounce.m

@implementation NSObject (Debounce)

- (void)debounce:(SEL)action delay:(NSTimeInterval)delay
{
  __weak typeof(self) weakSelf = self;
  [NSObject cancelPreviousPerformRequestsWithTarget:weakSelf selector:action object:nil];
  [weakSelf performSelector:action withObject:nil afterDelay:delay];
}

@end

We should use weakSelf in line 7.

If we use strong self, runloop will retain current object; and if running of cancelPreviousPerformRequestsWithTarget:selector:object: release current object, the next line of code will cause crash.

See a more detail explain here in Chinese.