Selectize Cache Plugin... beginning.

plugin.js

Selectize.registerPlugin('local_storage_cache', function(options) {
  var self  = this;
	var Store = null;

	options = $.extend({
		lifeTime:         -1, // Store forever
		keyCacheTimeName: 'meta_ct_',
		keyLifeTimeName:  'meta_lt_'
	}, options);

	var supportsLocalStorage = function() {
		if(typeof localStorage === 'undefined' || typeof JSON === 'undefined') {
			return false;
		}else{
			Store = window.localStorage;
			return true;
		}
	};

	var cacheItem = function(itemListKey, itemList) {
		if(!supportsLocalStorage()) return false;

		var keyCacheTimeName = options.keyCacheTimeName + itemListKey,
			keyLifeTimeName  = options.keyLifeTimeName + itemListKey;

		var cacheTime = new Date();
		Store.setItem(itemListKey, JSON.stringify(itemList)); // Store the actual data
		Store.setItem(keyCacheTimeName, cacheTime.getTime() / 1000); // Store when the cache was created
		Store.setItem(keyLifeTimeName, options.lifeTime); // Store how long we want to keep the cache for

		return true;
	};

	var getCachedItem = function(itemListKey) {
		if(!supportsLocalStorage()) return false;

		// If the value doesn't exist, return false.
		if(Store.getItem(itemListKey) === null) return false;

		var keyCacheTimeName = options.keyCacheTimeName + itemListKey,
			keyLifeTimeName  = options.keyLifeTimeName + itemListKey;

		var cacheTime = new Date();
		if(Store.getItem(itemListKey) === -1) {
			return Store.getItem(itemListKey); // Infinite store.
		}else{
			// Has the data expired? Remove it. It's no longer needed.
			if((cacheTime.getTime() / 1000) - Store.getItem(keyCacheTimeName) > Store.getItem(keyLifeTimeName)) {
				Store.removeItem(itemListKey);
				Store.removeItem(keyCacheTimeName);
				Store.removeItem(keyLifeTimeName);
				return false;
			}

			return JSON.parse(Store.getItem(itemListKey));
		}
	};

	hook.after(this, 'load', function() {
		// Cache layer
		if(this.lastQuery === "") return;
		var cachedData = getCachedItem(this.lastQuery);
		if($.isEmptyObject(this.options) && !cachedData) {
			cacheItem(this.lastQuery, this.options); // Store it.
		}
	});
});