angular-local-storage.js

var angularLocalStorage = angular.module('LocalStorageModule', []);

angularLocalStorage.provider('localStorageService', function() {

  // You should set a prefix to avoid overwriting any local storage variables from the rest of your app
  // e.g. localStorageServiceProvider.setPrefix('yourAppName');
  // With provider you can use config as this:
  // myApp.config(function (localStorageServiceProvider) {
  //    localStorageServiceProvider.prefix = 'yourAppName';
  // });
  this.prefix = 'ls';

  // You could change web storage type localstorage or sessionStorage
  this.storageType = 'localStorage';
  
  // Define if cookie fallback should be used when localStorage fails
  this.cookieFallback = true;

  // Cookie options (usually in case of fallback)
  // expiry = Number of days before cookies expire // 0 = Does not expire
  // path = The web path the cookie represents
  this.cookie = {
    expiry: 30,
    path: '/'
  };

  // Send signals for each of the following actions?
  this.notify = {
    setItem: true,
    removeItem: false
  };

  // Setter for the prefix
  this.setPrefix = function(prefix) {
    this.prefix = prefix;
    return this;
  };

   // Setter for the storageType
   this.setStorageType = function(storageType) {
     this.storageType = storageType;
     return this;
   };
   
    // Setter for the cookieFallback switch
   this.setCookieFallback = function(cookieFallback) {
     this.cookieFallback = !!cookieFallback;
     return this;
   };

  // Setter for cookie config
  this.setStorageCookie = function(exp, path) {
    this.cookie.expiry = exp;
    this.cookie.path = path;
    return this;
  };

  // Setter for cookie domain
  this.setStorageCookieDomain = function(domain) {
    this.cookie.domain = domain;
    return this;
  };

  // Setter for notification config
  // itemSet & itemRemove should be booleans
  this.setNotify = function(itemSet, itemRemove) {
    this.notify = {
      setItem: itemSet,
      removeItem: itemRemove
    };
    return this;
  };

  this.$get = ['$rootScope', '$window', '$document', '$parse', function($rootScope, $window, $document, $parse) {
    var self = this;
    var prefix = self.prefix;
    var cookie = self.cookie;
    var notify = self.notify;
    var storageType = self.storageType;
    var webStorage;

    // When Angular's $document is not available
    if (!$document) {
      $document = document;
    } else if ($document[0]) {
      $document = $document[0];
    }

    // If there is a prefix set in the config lets use that with an appended period for readability
    if (prefix.substr(-1) !== '.') {
      prefix = !!prefix ? prefix + '.' : '';
    }
    var deriveQualifiedKey = function(key) {
      return prefix + key;
    };
    // Checks the browser to see if local storage is supported
    var browserSupportsLocalStorage = (function () {
      try {
        var supported = (storageType in $window && $window[storageType] !== null);

        // When Safari (OS X or iOS) is in private browsing mode, it appears as though localStorage
        // is available, but trying to call .setItem throws an exception.
        //
        // "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage
        // that exceeded the quota."
        var key = deriveQualifiedKey('__' + Math.round(Math.random() * 1e7));
        if (supported) {
          webStorage = $window[storageType];
          webStorage.setItem(key, '');
          webStorage.removeItem(key);
        }

        return supported;
      } catch (e) {
        storageType = 'cookie';
        $rootScope.$broadcast('LocalStorageModule.notification.error', e.message);
        return false;
      }
    }());

    // Directly adds a value to local storage
    // If local storage is not available in the browser use cookies
    // Example use: localStorageService.add('library','angular');
    var addToLocalStorage = function (key, value) {
      // Let's convert undefined values to null to get the value consistent
      if (isUndefined(value)) {
        value = null;
      } else {
        value = toJson(value);
      }

      // If this browser does not support local storage use cookies
      if ((!browserSupportsLocalStorage && self.cookieFallback) || self.storageType === 'cookie') {
        if (!browserSupportsLocalStorage) {
            $rootScope.$broadcast('LocalStorageModule.notification.warning', 'LOCAL_STORAGE_NOT_SUPPORTED');
        }

        if (notify.setItem) {
          $rootScope.$broadcast('LocalStorageModule.notification.setitem', {key: key, newvalue: value, storageType: 'cookie'});
        }
        return addToCookies(key, value);
      }

      try {
        if (webStorage) {webStorage.setItem(deriveQualifiedKey(key), value)};
        if (notify.setItem) {
          $rootScope.$broadcast('LocalStorageModule.notification.setitem', {key: key, newvalue: value, storageType: self.storageType});
        }
      } catch (e) {
        $rootScope.$broadcast('LocalStorageModule.notification.error', e.message);
		if(self.cookieFallback) {
          return addToCookies(key, value);
		} else {
		  return false;
		}
      }
      return true;
    };

    // Directly get a value from local storage
    // Example use: localStorageService.get('library'); // returns 'angular'
    var getFromLocalStorage = function (key) {

      if (!browserSupportsLocalStorage || self.storageType === 'cookie') {
        if (!browserSupportsLocalStorage) {
          $rootScope.$broadcast('LocalStorageModule.notification.warning','LOCAL_STORAGE_NOT_SUPPORTED');
        }

        return getFromCookies(key);
      }

      var item = webStorage ? webStorage.getItem(deriveQualifiedKey(key)) : null;
      // angular.toJson will convert null to 'null', so a proper conversion is needed
      // FIXME not a perfect solution, since a valid 'null' string can't be stored
      if (!item || item === 'null') {
        return null;
      }

      try {
        return JSON.parse(item);
      } catch (e) {
        return item;
      }
    };

    // Remove an item from local storage
    // Example use: localStorageService.remove('library'); // removes the key/value pair of library='angular'
    var removeFromLocalStorage = function () {
      var i, key;
      for (i=0; i<arguments.length; i++) {
        key = arguments[i];
        if (!browserSupportsLocalStorage || self.storageType === 'cookie') {
          if (!browserSupportsLocalStorage) {
            $rootScope.$broadcast('LocalStorageModule.notification.warning', 'LOCAL_STORAGE_NOT_SUPPORTED');
          }

          if (notify.removeItem) {
            $rootScope.$broadcast('LocalStorageModule.notification.removeitem', {key: key, storageType: 'cookie'});
          }
          removeFromCookies(key);
        }
        else {
          try {
            webStorage.removeItem(deriveQualifiedKey(key));
            if (notify.removeItem) {
              $rootScope.$broadcast('LocalStorageModule.notification.removeitem', {
                key: key,
                storageType: self.storageType
              });
            }
          } catch (e) {
            $rootScope.$broadcast('LocalStorageModule.notification.error', e.message);
            removeFromCookies(key);
          }
        }
      }
    };

    // Return array of keys for local storage
    // Example use: var keys = localStorageService.keys()
    var getKeysForLocalStorage = function () {

      if (!browserSupportsLocalStorage) {
        $rootScope.$broadcast('LocalStorageModule.notification.warning', 'LOCAL_STORAGE_NOT_SUPPORTED');
        return false;
      }

      var prefixLength = prefix.length;
      var keys = [];
      for (var key in webStorage) {
        // Only return keys that are for this app
        if (key.substr(0,prefixLength) === prefix) {
          try {
            keys.push(key.substr(prefixLength));
          } catch (e) {
            $rootScope.$broadcast('LocalStorageModule.notification.error', e.Description);
            return [];
          }
        }
      }
      return keys;
    };

    // Remove all data for this app from local storage
    // Also optionally takes a regular expression string and removes the matching key-value pairs
    // Example use: localStorageService.clearAll();
    // Should be used mostly for development purposes
    var clearAllFromLocalStorage = function (regularExpression) {

      // Setting both regular expressions independently
      // Empty strings result in catchall RegExp
      var prefixRegex = !!prefix ? new RegExp('^' + prefix) : new RegExp();
      var testRegex = !!regularExpression ? new RegExp(regularExpression) : new RegExp();

      if (!browserSupportsLocalStorage || self.storageType === 'cookie') {
        if (!browserSupportsLocalStorage) {
          $rootScope.$broadcast('LocalStorageModule.notification.warning', 'LOCAL_STORAGE_NOT_SUPPORTED');
        }
        return clearAllFromCookies();
      }

      var prefixLength = prefix.length;

      for (var key in webStorage) {
        // Only remove items that are for this app and match the regular expression
        if (prefixRegex.test(key) && testRegex.test(key.substr(prefixLength))) {
          try {
            removeFromLocalStorage(key.substr(prefixLength));
          } catch (e) {
            $rootScope.$broadcast('LocalStorageModule.notification.error',e.message);
            return clearAllFromCookies();
          }
        }
      }
      return true;
    };

    // Checks the browser to see if cookies are supported
    var browserSupportsCookies = (function() {
      try {
        return $window.navigator.cookieEnabled ||
          ("cookie" in $document && ($document.cookie.length > 0 ||
          ($document.cookie = "test").indexOf.call($document.cookie, "test") > -1));
      } catch (e) {
          $rootScope.$broadcast('LocalStorageModule.notification.error', e.message);
          return false;
      }
    }());

    // Directly adds a value to cookies
    // Typically used as a fallback is local storage is not available in the browser
    // Example use: localStorageService.cookie.add('library','angular');
    var addToCookies = function (key, value, daysToExpiry) {

      if (isUndefined(value)) {
        return false;
      } else if(isArray(value) || isObject(value)) {
        value = toJson(value);
      }

      if (!browserSupportsCookies) {
        $rootScope.$broadcast('LocalStorageModule.notification.error', 'COOKIES_NOT_SUPPORTED');
        return false;
      }

      try {
        var expiry = '',
            expiryDate = new Date(),
            cookieDomain = '';

        if (value === null) {
          // Mark that the cookie has expired one day ago
          expiryDate.setTime(expiryDate.getTime() + (-1 * 24 * 60 * 60 * 1000));
          expiry = "; expires=" + expiryDate.toGMTString();
          value = '';
        } else if (isNumber(daysToExpiry) && daysToExpiry !== 0) {
          expiryDate.setTime(expiryDate.getTime() + (daysToExpiry * 24 * 60 * 60 * 1000));
          expiry = "; expires=" + expiryDate.toGMTString();
        } else if (cookie.expiry !== 0) {
          expiryDate.setTime(expiryDate.getTime() + (cookie.expiry * 24 * 60 * 60 * 1000));
          expiry = "; expires=" + expiryDate.toGMTString();
        }
        if (!!key) {
          var cookiePath = "; path=" + cookie.path;
          if(cookie.domain){
            cookieDomain = "; domain=" + cookie.domain;
          }
          $document.cookie = deriveQualifiedKey(key) + "=" + encodeURIComponent(value) + expiry + cookiePath + cookieDomain;
        }
      } catch (e) {
        $rootScope.$broadcast('LocalStorageModule.notification.error',e.message);
        return false;
      }
      return true;
    };

    // Directly get a value from a cookie
    // Example use: localStorageService.cookie.get('library'); // returns 'angular'
    var getFromCookies = function (key) {
      if (!browserSupportsCookies) {
        $rootScope.$broadcast('LocalStorageModule.notification.error', 'COOKIES_NOT_SUPPORTED');
        return false;
      }

      var cookies = $document.cookie && $document.cookie.split(';') || [];
      for(var i=0; i < cookies.length; i++) {
        var thisCookie = cookies[i];
        while (thisCookie.charAt(0) === ' ') {
          thisCookie = thisCookie.substring(1,thisCookie.length);
        }
        if (thisCookie.indexOf(deriveQualifiedKey(key) + '=') === 0) {
          var storedValues = decodeURIComponent(thisCookie.substring(prefix.length + key.length + 1, thisCookie.length))
          try {
            return JSON.parse(storedValues);
          } catch(e) {
            return storedValues
          }
        }
      }
      return null;
    };

    var removeFromCookies = function (key) {
      addToCookies(key,null);
    };

    var clearAllFromCookies = function () {
      var thisCookie = null, thisKey = null;
      var prefixLength = prefix.length;
      var cookies = $document.cookie.split(';');
      for(var i = 0; i < cookies.length; i++) {
        thisCookie = cookies[i];

        while (thisCookie.charAt(0) === ' ') {
          thisCookie = thisCookie.substring(1, thisCookie.length);
        }

        var key = thisCookie.substring(prefixLength, thisCookie.indexOf('='));
        removeFromCookies(key);
      }
    };

    var getStorageType = function() {
      return storageType;
    };

    // Add a listener on scope variable to save its changes to local storage
    // Return a function which when called cancels binding
    var bindToScope = function(scope, key, def, lsKey) {
      lsKey = lsKey || key;
      var value = getFromLocalStorage(lsKey);

      if (value === null && isDefined(def)) {
        value = def;
      } else if (isObject(value) && isObject(def)) {
        value = extend(def, value);
      }

      $parse(key).assign(scope, value);

      return scope.$watch(key, function(newVal) {
        addToLocalStorage(lsKey, newVal);
      }, isObject(scope[key]));
    };

    // Return localStorageService.length
    // ignore keys that not owned
    var lengthOfLocalStorage = function() {
      var count = 0;
      var storage = $window[storageType];
      for(var i = 0; i < storage.length; i++) {
        if(storage.key(i).indexOf(prefix) === 0 ) {
          count++;
        }
      }
      return count;
    };

    return {
      isSupported: browserSupportsLocalStorage,
      getStorageType: getStorageType,
      set: addToLocalStorage,
      add: addToLocalStorage, //DEPRECATED
      get: getFromLocalStorage,
      keys: getKeysForLocalStorage,
      remove: removeFromLocalStorage,
      clearAll: clearAllFromLocalStorage,
      bind: bindToScope,
      deriveKey: deriveQualifiedKey,
      length: lengthOfLocalStorage,
      cookie: {
        isSupported: browserSupportsCookies,
        set: addToCookies,
        add: addToCookies, //DEPRECATED
        get: getFromCookies,
        remove: removeFromCookies,
        clearAll: clearAllFromCookies
      }
    };
  }];
});