Evented JavaScript for the browser

This script adds the EventEmitter class to your browser.

So you can listen for and emit events from what ever objects you choose.

EventEmitter deters from the NodeJS implementation slightly but it is lighter and faster.

Example

// Initialise the EventEmitter
var ee = new EventEmitter();

// Initialise the listener function
function myListener() {
	console.log('The foo event was emitted.');
}

// Add the listener
ee.addListener('foo', myListener);

// Emit the foo event
ee.emit('foo'); // The listener function is now called

// Remove the listener
ee.removeListener('foo', myListener);

// Log the array of listeners to show that it has been removed
console.log(ee.listeners('foo'));

API

This is just the method list for the API. For in-depth argument documentation please check the source. Every method has a JSDoc comment block that explains every aspect of the method.

• EventEmitter.Event(type, listener, scope, once) - Event class, used internally for listener managing.
  • EventEmitter.Event.fire(args) - Calls the events listener with the specified array of arguments.
• EventEmitter.eachListener(type, callback) - Loops over every listener for an event passing them to the callback.
• EventEmitter.addListener(type, listener, scope, once) - Adds an event listener for the specified event.
• EventEmitter.on(type, listener, scope, once) - Alias of the addListener method.
• EventEmitter.once(type, listener, scope) - Alias of the addListener method but will remove the event after the first use.
• EventEmitter.removeListener(type, listener) - Removes the a listener for the specified event.
• EventEmitter.removeAllListeners(type) - Removes all listeners for a specified event.
• EventEmitter.listeners(type) - Retrieves the array of listeners for a specified event.
• EventEmitter.emit(type, args) - Emits an event executing all appropriate listeners.

Tests

EventEmitter is tested and working in the following browsers.

• Chrome
• Firefox
• Safari
• Opera
• IE 5+

If you test it in something a little more obscure, please let me know how it turned out.

To test, simply run test.html in the test folder.

Author

EventEmitter was written by Oliver Caldwell.

Licences

MIT

Copyright (C) 2011 Oliver Caldwell

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

GPL

Copyright (C) 2011 Oliver Caldwell

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.