EventedArray

An Array-like data structure in JavaScript which allows you to register callbacks on accessor/mutator operations.

Sometimes you want a simple data structure such as an Array ([1,2,3,4]) that you can attach callbacks to, so that accessor & mutator actions like set, getting, popping and shifting values from the Array will trigger those callbacks.

Similar projects:

Unlike those projects, this one also lets you create a fixed size array so that older values are shifted() off the front as new values are pushed() on the end.

Show me:

Simple animation demo - http://darrenn.github.io/EventedArray

Flickr image search demo - /test-jsonp.html

Higher-order functional version - test-fanimation.html

var e = new EventedArray(1,2,3,4,5);

// Simple setter/getter

e.toString() // [1,2,3,4,5]
e.set(1)
e.toString() // [1,2,3,4,5,1]
e.get(2) // returns 3

// Define a callback on 'set'
e.register('set', function(i) { console.log( i + ' was set!'); });

e.set('a') // console: a was set!

// Create a set sized array (buffered)

var e = new EventedArray();
e.setBuffer(4);
e.set(1,2,3,4,5);
e.toString(); // "[2,3,4,5]"
e.set('howdy');
e.toString(); // "[3,4,5,'howdy']"

Lispy-flavored version

This whole shebang got started while I was playing around with ClojureScript and Scheme and needed a listenable list. After doing that I realized I could translate those functions easily with minimal CoffeeScript to do the same thing in my JavaScript projects. You can see that here and play with it in /test/test-fanimation.html

Dependencies

Underscore.js - I mixin a grab bag of the collection functions from Underscore to make it easy to access and iterate over the values

How to use:

Is ready to go with Node.js, RequireJS and dropped into the global window object. Just pull it in how you like (but remember, it needs Underscore.js)

License:

The MIT License (MIT)

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.