callback-registry

Intro

A simple registry for callbacks that allows you to add one or more callbacks under some key and then execute all callbacks under some key.

Example:

const registryFactory = require('callback-registry');

const registry = registryFactory();

// add a new callback for that event key
registry.add('event-key', function(){
    console.log('the event occurred')
});

// execute all callbacks that were registred for that key
registry.execute('event-key');

Passing arguments

You can pass any arguments to the callbacks when you execute them

// execute all callbacks that were registred for that key
registry.execute('event-key', arg1, arg2, arg3);

Returning results

The execute method returns an array with the results returned from the callbacks.

Removing a callback

When you add a new callback a function is returned that can be used to unsubscribe

// A callback that will be called just the first time
var unsubscribe = registry.add('event-key', function(){
    console.log('the event occurred');
    unsubscribe();
});

Change log

• 2.3.2
  • fix case where unsubscribe function removes all subscriptions with the same callback reference
• 2.1.1
  • return empty array as result if no subscribers
  • catch errors in user callbacks (returns undefined in the result if error)