Notifications and KVO observers used by the AIM team
AIMNotificationObserver
is a notification observer that should be used as alternative for [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(getNotification:) name:name object:sender]
. AIMObserver
is a KVO observer that should be used as an alternative for [obj addObserver:self forKeyPath:keyPath options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld|NSKeyValueObservingOptionInitial context:NULL];
. It is guaranteed that observer is removed when the object is deallocated.
#Usage
NSNotificationCenter observer:
@interface ViewController ()
@property (strong, nonatomic) AIMNotificationObserver *observer;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
__weak __typeof(self) weakSelf = self;
self.observer = [AIMNotificationObserver observeName:@"changeBackground" onChange:^(NSNotification *notification) {
//use weakSelf to avoid strong reference cycles
weakSelf.view.backgroundColor = [UIColor red];
}];
}
@end
KVO observer:
@interface ViewController ()
@property (strong, nonatomic) AIMObserver *observer;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
__weak __typeof(self) weakSelf = self;
self.observer = [AIMObserver observed:self.view.layer keyPath:@"backgroundColor" onChange:^(NSDictionary *change) {
//use weakSelf to avoid strong reference cycles
[weakSelf.button setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
}];
}
@end
#Installation
Use the CocoaPods.
Add to your Podfile
pod 'AIMObservers'
and then call
pod install
and import
#import "AIMNotificationObserver.h"
or
#import "AIMObserver.h"
#Example
In the example, AIMNotificationObserver
is used to change the background of the main view, as respond to a notification and AIMObserver
is used to change button text color, when background has changed (pretty lame usage, but in a real life application, you could use notification and KVO in a much more complicated way).