html5 localStorage error with Safari: “QUOTA_EXCEE

Question

My webapp have javascript errors in ios safari private browsing:

JavaScript:error

undefined

QUOTA_EXCEEDED_ERR:DOM Exception 22:An attempt was made to add something to storage...

my code:

localStorage.setItem('test',1)

Answer 1

I had the same problem using Ionic framework (Angular + Cordova). I know this not solve the problem, but it's the code for Angular Apps based on the answers above. You will have a ephemeral solution for localStorage on iOS version of Safari.

Here is the code:

angular.module('myApp.factories', [])
.factory('$fakeStorage', [
    function(){
        function FakeStorage() {};
        FakeStorage.prototype.setItem = function (key, value) {
            this[key] = value;
        };
        FakeStorage.prototype.getItem = function (key) {
            return typeof this[key] == 'undefined' ? null : this[key];
        }
        FakeStorage.prototype.removeItem = function (key) {
            this[key] = undefined;
        };
        FakeStorage.prototype.clear = function(){
            for (var key in this) {
                if( this.hasOwnProperty(key) )
                {
                    this.removeItem(key);
                }
            }
        };
        FakeStorage.prototype.key = function(index){
            return Object.keys(this)[index];
        };
        return new FakeStorage();
    }
])
.factory('$localstorage', [
    '$window', '$fakeStorage',
    function($window, $fakeStorage) {
        function isStorageSupported(storageName) 
        {
            var testKey = 'test',
                storage = $window[storageName];
            try
            {
                storage.setItem(testKey, '1');
                storage.removeItem(testKey);
                return true;
            } 
            catch (error) 
            {
                return false;
            }
        }
        var storage = isStorageSupported('localStorage') ? $window.localStorage : $fakeStorage;
        return {
            set: function(key, value) {
                storage.setItem(key, value);
            },
            get: function(key, defaultValue) {
                return storage.getItem(key) || defaultValue;
            },
            setObject: function(key, value) {
                storage.setItem(key, JSON.stringify(value));
            },
            getObject: function(key) {
                return JSON.parse(storage.getItem(key) || '{}');
            },
            remove: function(key){
                storage.removeItem(key);
            },
            clear: function() {
                storage.clear();
            },
            key: function(index){
                storage.key(index);
            }
        }
    }
]);

Source: https://gist.github.com/jorgecasar/61fda6590dc2bb17e871

Enjoy your coding!

Answer 2

To expand on others' answers, here is a compact solution that doesn't expose/add any new variables. It doesn't cover all bases, but it should suit most people who just want a single page app to remain functional (despite no data persistence after reload).

(function(){
    try {
        localStorage.setItem('_storage_test', 'test');
        localStorage.removeItem('_storage_test');
    } catch (exc){
        var tmp_storage = {};
        var p = '__unique__';  // Prefix all keys to avoid matching built-ins
        Storage.prototype.setItem = function(k, v){
            tmp_storage[p + k] = v;
        };
        Storage.prototype.getItem = function(k){
            return tmp_storage[p + k] === undefined ? null : tmp_storage[p + k];
        };
        Storage.prototype.removeItem = function(k){
            delete tmp_storage[p + k];
        };
        Storage.prototype.clear = function(){
            tmp_storage = {};
        };
    }
})();

Answer 3

In my context, just developed a class abstraction. When my application is launched, i check if localStorage is working by calling getStorage(). This function also return :

• either localStorage if localStorage is working
• or an implementation of a custom class LocalStorageAlternative

In my code i never call localStorage directly. I call cusStoglobal var, i had initialised by calling getStorage().

This way, it works with private browsing or specific Safari versions

function getStorage() {

    var storageImpl;

     try { 
        localStorage.setItem("storage", ""); 
        localStorage.removeItem("storage");
        storageImpl = localStorage;
     }
     catch (err) { 
         storageImpl = new LocalStorageAlternative();
     }

    return storageImpl;

}

function LocalStorageAlternative() {

    var structureLocalStorage = {};

    this.setItem = function (key, value) {
        structureLocalStorage[key] = value;
    }

    this.getItem = function (key) {
        if(typeof structureLocalStorage[key] != 'undefined' ) {
            return structureLocalStorage[key];
        }
        else {
            return null;
        }
    }

    this.removeItem = function (key) {
        structureLocalStorage[key] = undefined;
    }
}

cusSto = getStorage();

Answer 4

The fix posted on above link did not work for me. This did:

function isLocalStorageNameSupported() {
  var testKey = 'test', storage = window.localStorage;
  try {
    storage.setItem(testKey, '1');
    storage.removeItem(testKey);
    return true;
  } catch (error) {
    return false;
  }
}

Derived from http://m.cg/post/13095478393/detect-private-browsing-mode-in-mobile-safari-on-ios5

Answer 5

The following script solved my problem:

// Fake localStorage implementation. 
// Mimics localStorage, including events. 
// It will work just like localStorage, except for the persistant storage part. 

var fakeLocalStorage = function() {
  var fakeLocalStorage = {};
  var storage; 

  // If Storage exists we modify it to write to our fakeLocalStorage object instead. 
  // If Storage does not exist we create an empty object. 
  if (window.Storage && window.localStorage) {
    storage = window.Storage.prototype; 
  } else {
    // We don't bother implementing a fake Storage object
    window.localStorage = {}; 
    storage = window.localStorage; 
  }

  // For older IE
  if (!window.location.origin) {
    window.location.origin = window.location.protocol + "//" + window.location.hostname + (window.location.port ? ':' + window.location.port: '');
  }

  var dispatchStorageEvent = function(key, newValue) {
    var oldValue = (key == null) ? null : storage.getItem(key); // `==` to match both null and undefined
    var url = location.href.substr(location.origin.length);
    var storageEvent = document.createEvent('StorageEvent'); // For IE, http://stackoverflow.com/a/25514935/1214183

    storageEvent.initStorageEvent('storage', false, false, key, oldValue, newValue, url, null);
    window.dispatchEvent(storageEvent);
  };

  storage.key = function(i) {
    var key = Object.keys(fakeLocalStorage)[i];
    return typeof key === 'string' ? key : null;
  };

  storage.getItem = function(key) {
    return typeof fakeLocalStorage[key] === 'string' ? fakeLocalStorage[key] : null;
  };

  storage.setItem = function(key, value) {
    dispatchStorageEvent(key, value);
    fakeLocalStorage[key] = String(value);
  };

  storage.removeItem = function(key) {
    dispatchStorageEvent(key, null);
    delete fakeLocalStorage[key];
  };

  storage.clear = function() {
    dispatchStorageEvent(null, null);
    fakeLocalStorage = {};
  };
};

// Example of how to use it
if (typeof window.localStorage === 'object') {
  // Safari will throw a fit if we try to use localStorage.setItem in private browsing mode. 
  try {
    localStorage.setItem('localStorageTest', 1);
    localStorage.removeItem('localStorageTest');
  } catch (e) {
    fakeLocalStorage();
  }
} else {
  // Use fake localStorage for any browser that does not support it.
  fakeLocalStorage();
}

It checks if localStorage exists and can be used and in the negative case, it creates a fake local storage and uses it instead of the original localStorage. Please let me know if you need further information.

Answer 6

As mentioned in other answers, you'll always get the QuotaExceededError in Safari Private Browser Mode on both iOS and OS X when localStorage.setItem (or sessionStorage.setItem) is called.

One solution is to do a try/catch or Modernizr check in each instance of using setItem.

However if you want a shim that simply globally stops this error being thrown, to prevent the rest of your JavaScript from breaking, you can use this:

https://gist.github.com/philfreo/68ea3cd980d72383c951

// Safari, in Private Browsing Mode, looks like it supports localStorage but all calls to setItem
// throw QuotaExceededError. We're going to detect this and just silently drop any calls to setItem
// to avoid the entire page breaking, without having to do a check at each usage of Storage.
if (typeof localStorage === 'object') {
    try {
        localStorage.setItem('localStorage', 1);
        localStorage.removeItem('localStorage');
    } catch (e) {
        Storage.prototype._setItem = Storage.prototype.setItem;
        Storage.prototype.setItem = function() {};
        alert('Your web browser does not support storing settings locally. In Safari, the most common cause of this is using "Private Browsing Mode". Some settings may not save or some features may not work properly for you.');
    }
}