Add Observer to BOOL variable

Question

Is it possible to add observers to simple variables such as BOOLs or NSIntegers and see when they change?

Thanks!

Answer 1

I believe what you meant was: How to get INT or BOOL value from the 'change' dictionary if the property has changed.

You can simply do it this way:

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary *)change
                       context:(void *)context
{
    if ([keyPath isEqualToString:@"mySetting"])
    {
        NSNumber *mySettingNum = [change objectForKey:NSKeyValueChangeNewKey];
        BOOL newSetting = [mySettingNum boolValue];
        NSLog(@"mySetting is %s", (newSetting ? "true" : "false")); 
        return;
    }

    [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}