openfoodnetwork/app/assets/javascripts/shared/angular-local-storage.js

/*
 * Angular.js localStorage module
 * https://github.com/agrublev/angularLocalStorage
 */

(function (window, angular, undefined) {
	'use strict';

	angular.module('angularLocalStorage', ['ngCookies']).factory('storage', ['$parse', '$cookieStore', '$window', '$log', function ($parse, $cookieStore, $window, $log) {
		/**
		 * Global Vars
		 */
		var storage = (typeof $window.localStorage === 'undefined') ? undefined : $window.localStorage;
		var supported = typeof storage !== 'undefined';

		var privateMethods = {
			/**
			 * Pass any type of a string from the localStorage to be parsed so it returns a usable version (like an Object)
			 * @param res - a string that will be parsed for type
			 * @returns {*} - whatever the real type of stored value was
			 */
			parseValue: function (res) {
				var val;
				try {
					val = angular.fromJson(res);
					if (typeof val === 'undefined') {
						val = res;
					}
					if (val === 'true') {
						val = true;
					}
					if (val === 'false') {
						val = false;
					}
					if ($window.parseFloat(val) === val && !angular.isObject(val)) {
						val = $window.parseFloat(val);
					}
				} catch (e) {
					val = res;
				}
				return val;
			}
		};

		var publicMethods = {
			/**
			 * Set - let's you set a new localStorage key pair set
			 * @param key - a string that will be used as the accessor for the pair
			 * @param value - the value of the localStorage item
			 * @returns {*} - will return whatever it is you've stored in the local storage
			 */
			set: function (key, value) {
				if (!supported) {
					try {
						$cookieStore.put(key, value);
						return value;
					} catch(e) {
						$log.log('Local Storage not supported, make sure you have angular-cookies enabled.');
					}
				}
				var saver = angular.toJson(value);
				storage.setItem(key, saver);
				return privateMethods.parseValue(saver);
			},

			/**
			 * Get - let's you get the value of any pair you've stored
			 * @param key - the string that you set as accessor for the pair
			 * @returns {*} - Object,String,Float,Boolean depending on what you stored
			 */
			get: function (key) {
				if (!supported) {
					try {
						return privateMethods.parseValue($.cookie(key));
					} catch (e) {
						return null;
					}
				}
				var item = storage.getItem(key);
				return privateMethods.parseValue(item);
			},

			/**
			 * Remove - let's you nuke a value from localStorage
			 * @param key - the accessor value
			 * @returns {boolean} - if everything went as planned
			 */
			remove: function (key) {
				if (!supported) {
					try {
						$cookieStore.remove(key);
						return true;
					} catch (e) {
						return false;
					}
				}
				storage.removeItem(key);
				return true;
			},

			/**
			 * Bind - let's you directly bind a localStorage value to a $scope variable
			 * @param {Angular $scope} $scope - the current scope you want the variable available in
			 * @param {String} key - the name of the variable you are binding
			 * @param {Object} opts - (optional) custom options like default value or unique store name
			 * Here are the available options you can set:
			 * * defaultValue: the default value
			 * * storeName: add a custom store key value instead of using the scope variable name
			 * @returns {*} - returns whatever the stored value is
			 */
			bind: function ($scope, key, opts) {
				var defaultOpts = {
					defaultValue: '',
					storeName: ''
				};
				// Backwards compatibility with old defaultValue string
				if (angular.isString(opts)) {
					opts = angular.extend({},defaultOpts,{defaultValue:opts});
				} else {
					// If no defined options we use defaults otherwise extend defaults
					opts = (angular.isUndefined(opts)) ? defaultOpts : angular.extend(defaultOpts,opts);
				}

				// Set the storeName key for the localStorage entry
				// use user defined in specified
				var storeName = opts.storeName || key;

				// If a value doesn't already exist store it as is
				if (!publicMethods.get(storeName)) {
          publicMethods.set(storeName, $parse(key)($scope) || opts.defaultValue);
				} else {
          // If it does exist assign it to the $scope value
          $parse(key).assign($scope, publicMethods.get(storeName));
        }


				// Register a listener for changes on the $scope value
				// to update the localStorage value
				$scope.$watch(key, function (val) {
					if (angular.isDefined(val)) {
						publicMethods.set(storeName, val);
					}
				}, true);

				return publicMethods.get(storeName);
			},
			/**
			 * Unbind - let's you unbind a variable from localStorage while removing the value from both
			 * the localStorage and the local variable and sets it to null
			 * @param $scope - the scope the variable was initially set in
			 * @param key - the name of the variable you are unbinding
			 * @param storeName - (optional) if you used a custom storeName you will have to specify it here as well
			 */
			unbind: function($scope,key,storeName) {
				storeName = storeName || key;
				$parse(key).assign($scope, null);
				$scope.$watch(key, function () { });
				publicMethods.remove(storeName);
			},
			/**
			 * Clear All - let's you clear out ALL localStorage variables, use this carefully!
			 */
			clearAll: function() {
				storage.clear();
			}
		};

		return publicMethods;
	}]);

})(window, window.angular);