dseredinov / eventemitter

Node.js inspired EventEmitter for objective c.

Node.js inspired EventEmitter for objective c.

Use it

Copy the EventEmitter class into your project or add this line to your Podfile

pod 'EventEmitter', '~> 0.1.1'

Quick API overview

Register event listener on any object:

#import "EventEmitter.h"

NSObject* emitter = [[NSObject alloc] init];

__block BOOL ready = NO;

[emitter on:@"ready" notify:^() {
	NSLog(@"Yepp! The object is ready now!");
	ready = YES;
}];

[emitter on:@"event" callback:^(NSDictionary* data) {
	if (ready) {
		NSLog(@"Receive event with data: %@", data);
	}
}];

And later fire an event to the same object:

#import "EventEmitter.h"

NSObject* emitter = ...;

[emitter emit:@"ready"];

[emitter emit:@"event" data:@{
	@"type": @"somethinghappend",
	@"another key": @"another value",
}];

Implementation details

• The "original" API: http://nodejs.org/docs/latest/api/events.html
• use ARC (could be also enabled per file if your project does not use ARC)
• pure objective c, works on OSX and iOS
• Add a category to NSObject. More here: http://developer.apple.com/library/mac/#documentation/cocoa/conceptual/objectivec/chapters/occategories.html
• Use objc_setAssociatedObject and objc_getAssociatedObject to assign event listener to any object. More here: http://oleb.net/blog/2011/05/faking-ivars-in-objc-categories-with-associative-references/