LocalStorageHandler.js

/**
 * A class for easing HTML5 LocalStorage handling. Licensed under CC BY 3.0.
 * https://github.com/joaocunha/javascript-localstorage-handler/
 *
 * @author João Cunha - joao@joaocunha.net
 * @class LocalStorageHandler
 * @constructor
 */
;(function(win) {
    'use strict';

    var LocalStorageHandler = function() {

        /**
         * @property _ls
         * @private
         * @type Object
         */
        var _ls = win.localStorage;

        /**
         * @property length
         * @type Number
         */
        this.length = _ls.length;

        /**
         * @method get
         * @param key {String} Item key
         * @return {String|Object|Null}
         */
        this.get = function(key) {
            try {
                return JSON.parse(_ls.getItem(key));
            } catch(e) {
                return _ls.getItem(key);
            }
        };

        /**
         * @method set
         * @param key {String} Item key
         * @param val {String|Object} Item value
         * @return {String|Object} The value of the item just set
         */
        this.set = function(key, val) {
            _ls.setItem(key,JSON.stringify(val));
            return this.get(key);
        };

        /**
         * @method key
         * @param index {Number} Item index
         * @return {String|Null} The item key if found, null if not
         */
        this.key = function(index) {
            if (typeof index === 'number') {
                return _ls.key(index);
            }
        };

        /**
         * @method data
         * @return {Array|Null} An array containing all items in localStorage through key{string}-value{String|Object} pairs
         */
        this.data = function() {
            var i       = 0;
            var data    = [];

            while (_ls.key(i)) {
                data[i] = [_ls.key(i), this.get(_ls.key(i))];
                i++;
            }

            return data.length ? data : null;
        };

        /**
         * @method remove
         * @param keyOrIndex {String|Number} Item key or index (which will be converted to key anyway)
         * @return {Boolean} True if the key was found before deletion, false if not
         */
        this.remove = function(keyOrIndex) {
            var result = false;
            var key = (typeof keyOrIndex === 'number') ? this.key(keyOrIndex) : keyOrIndex;

            if (key in _ls) {
                result = true;
                _ls.removeItem(key);
            }

            return result;
        };

        /**
         * @method clear
         * @return {Number} The total of items removed
         */
        this.clear = function() {
            var len = _ls.length;
            _ls.clear();
            return len;
        };
    }

})(window);