A tiny, fast, zero-dependency event emitter
npm install eevA tiny, fast, zero-dependency event emitter for JavaScript.
- Less than 500 bytes minified + zipped
- Fast... see jsperf
- Zero dependencies
- Simple
Create an Eev instance.
``javascript`
var e = new Eev();
Then, add handlers as you see fit.
`javascript
e.on('some-event', function (data) {
alert('got ' + data);
});
e.on('some-event', function (data) {
console.log('got ' + data);
});
`
Remove handlers using off.
`javascript
function myHandler (data) { console.log(data); }
e.on('some-event', myHandler);
e.off('some-event', myHandler);
`
Trigger events using emit.
`javascript`
// The second parameter here is the data you wish to
// pass to the event handlers
e.emit('some-event', { foo: 'Bar' });
If you want a handler to only run once, you can do this:
`javascript
e.on('some-event', function foo () {
e.off('some-event', foo);
// Do stuff
});
`
You can register for multiple events at once like this:
`javascript
function myHandler (data) { console.log(data); }
e.on('event1 event2 etc', myHandler);
e.off('event1 event2 etc', myHandler);
`
Stopping propagation isn't build into Eev. If enough people ask for it, I'll bake it in. Meanwile, you can work around this limitation by doing something like this:
`js
;(function () {
var superOn = Eev.prototype.on;
Eev.prototype.on = function (names, fn) {
superOn.call(this, names, function (data) {
if (!data.isCanceled) {
return fn(data);
}
});
};
}());
`
With the above patch in place, you can do something like this in your event handlers:
`js``
e.on('some-event', function foo (data) {
data.isCanceled = true; // Now, no downstream handlers should be invoked
})
Just download eev.min.js, or use bower:
bower install eev
Or use npm: https://www.npmjs.com/package/eev
npm install --save eev
Copyright (c) 2015 Chris Davies
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.
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