NSNotificationsProvider: Subscribe to multiple notifications on an object with one call.

README.md

NSNotificationsProvider Category

By including the .h and .m files in this Gist, you can register a listener to numerous notifications on a notification emitter with a single call, providing a dictionary where the keys are the notification names, and the value are @selectors. Since you cannot directly put a @selector into a container, a macro is provided to turn the selector into an NSString.

Now you can do this:

[self.clusterLayer registerListener:self forNotifications:@{
    AGSClusterLayerDataLoadingProgressNotification: strSelector(dataLoadProgress:),
    AGSClusterLayerDataLoadingErrorNotification: strSelector(dataLoadError:),
    AGSClusterLayerClusteringProgressNotification: strSelector(clusteringProgress:)
}];

instead of this:

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(dataLoadProgress:)
                                             name:AGSClusterLayerDataLoadingProgressNotification
                                           object:self.clusterLayer];
[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(dataLoadError:)
                                             name:AGSClusterLayerDataLoadingErrorNotification
                                           object:self.clusterLayer];
[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(clusteringProgress:)
                                             name:AGSClusterLayerClusteringProgressNotification
                                           object:self.clusterLayer];

NSObject+NFNotificationsProvider.h

#import <Foundation/Foundation.h>

#define strSelector(a) NSStringFromSelector(@selector(a))

@interface NSObject (NFNotificationsProvider)
-(void)registerListener:(id)listener forNotifications:(NSDictionary *)notificationSelectors;
-(void)unRegisterListener:(id)listener fromNotifications:(NSArray *)notificationNames;
@end

NSObject+NFNotificationsProvider.m

#import "NSObject+NFNotificationsProvider.h"

@implementation NSObject (NFNotificationsProvider)
-(void)registerListener:(id)listener forNotifications:(NSDictionary *)notificationSelectors {
    for (id notificationName in notificationSelectors) {
        [[NSNotificationCenter defaultCenter] addObserver:listener
                                                 selector:NSSelectorFromString(notificationSelectors[notificationName])
                                                     name:notificationName
                                                   object:self];
    }
}

-(void)unRegisterListener:(id)listener fromNotifications:(NSArray *)notificationNames {
    for (id notificationName in notificationNames) {
        [[NSNotificationCenter defaultCenter] removeObserver:listener
                                                        name:notificationName
                                                      object:self];
    }
}
@end