Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
LocalStorage/SessionStorage Polyfill with Safari Private Browsing support.
// Refer to https://gist.github.com/remy/350433
try {
// Test webstorage existence.
if (!window.localStorage || !window.sessionStorage) throw "exception";
// Test webstorage accessibility - Needed for Safari private browsing.
localStorage.setItem('storage_test', 1);
localStorage.removeItem('storage_test');
} catch(e) {
(function () {
var Storage = function (type) {
function createCookie(name, value, days) {
var date, expires;
if (days) {
date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
expires = "; expires="+date.toGMTString();
} else {
expires = "";
}
document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
var nameEQ = name + "=",
ca = document.cookie.split(';'),
i, c;
for (i=0; i < ca.length; i++) {
c = ca[i];
while (c.charAt(0)==' ') {
c = c.substring(1,c.length); 2480
}
if (c.indexOf(nameEQ) == 0) {
return c.substring(nameEQ.length,c.length);
}
}
return null;
}
function setData(data) {
// Convert data into JSON and encode to accommodate for special characters.
data = encodeURIComponent(JSON.stringify(data));
// Create cookie.
if (type == 'session') {
createCookie(getSessionName(), data, 365);
} else {
createCookie('localStorage', data, 365);
}
}
function clearData() {
if (type == 'session') {
createCookie(getSessionName(), '', 365);
} else {
createCookie('localStorage', '', 365);
}
}
function getData() {
// Get cookie data.
var data = type == 'session' ? readCookie(getSessionName()) : readCookie('localStorage');
// If we have some data decode, parse and return it.
return data ? JSON.parse(decodeURIComponent(data)) : {};
}
function getSessionName() {
// If there is no name for this window, set one.
// To ensure it's unquie use the current timestamp.
if(!window.name) {
window.name = new Date().getTime();
}
return 'sessionStorage' + window.name;
}
// Initialise if there's already data.
var data = getData();
return {
length: 0,
clear: function () {
data = {};
this.length = 0;
clearData();
},
getItem: function (key) {
return data[key] === undefined ? null : data[key];
},
key: function (i) {
// not perfect, but works
var ctr = 0;
for (var k in data) {
if (ctr == i) return k;
else ctr++;
}
return null;
},
removeItem: function (key) {
delete data[key];
this.length--;
setData(data);
},
setItem: function (key, value) {
data[key] = value+''; // forces the value to a string
this.length++;
setData(data);
}
};
};
// Replace window.localStorage and window.sessionStorage with out custom
// implementation.
var localStorage = new Storage('local');
var sessionStorage = new Storage('session');
window.localStorage = localStorage;
window.sessionStorage = sessionStorage;
// For Safari private browsing need to also set the proto value.
window.localStorage.__proto__ = localStorage;
window.sessionStorage.__proto__ = sessionStorage;
})();
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.