Basic events emitter implementation.

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Basic events emitter implementation
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Typically, there are no strict restrictions on event names, as any string will be accepted. Usually it's a lowercase string with no spaces. Possible values: click, move, focus:item.
Functions can then be attached to objects, to be executed when an event is emitted. These functions are called listeners. Inside a listener function, this refers to the Emitter that the listener was attached to.

Installation ##

npm install cjs-emitter

Usage ##

Add the constructor to the scope:
var Emitter = require('cjs-emitter');

Create an instance:
var emitter = new Emitter();

Add listeners for some events:
emitter.addListener('click', function ( data ) { /* ... */ });
emitter.addListener('click', function ( data ) { /* ... */ });

Add listener that will be notified only one time:
emitter.once('click', function ( data ) { /* ... */ });

Add multiple listeners at once:
    click: function ( data ) {},
    close: function ( data ) {}

Remove all instances of the given callback:
emitter.removeListener('click', func1);

Remove all callbacks for the given event name:

Clears all events:

Execute each of the listeners in the given order with the supplied arguments:
emitter.emit('click', {src: panel1, dst: panel2});
emitter.emit('load', error, data);

Performance notes ##

It's a good idea to emit events only when there are some listeners:
if ( emitter.events['click'] ) {
    // notify listeners
    emitter.emit('click', {event: event});

Development mode ##

There is a global var DEVELOP which activates additional consistency checks and protection logic not available in release mode.

Contribution ##

If you have any problems or suggestions please open an issue according to the contribution rules.

License ##

cjs-emitter is released under the MIT License.