Global Session Storage

Global Storage

As of 2016-08-29. See the latest version.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name       Global Session Storage
// @namespace  http://legitspam.edu/
// @version    0.21
// @description  Global Storage
// @match      *://*/*
// @require	http://code.jquery.com/jquery-latest.js
// @author	http://blog.guya.net/2015/06/12/sharing-sessionstorage-between-tabs-for-secure-multi-tab-authentication/
// @grant	GM_getValue
// @grant	GM_setValue
// ==/UserScript==

var sessionStorage_transfer = function(event) {
    if(!event) { event = window.event; } // ie suq
    if(!event.newValue) return;          // do nothing if no value to work with
    if (event.key == 'getSessionStorage') {
        // another tab asked for the sessionStorage -> send it
        localStorage.setItem('sessionStorage', JSON.stringify(sessionStorage));
        // the other tab should now have it, so we're done with it.
        localStorage.removeItem('sessionStorage'); // <- could do short timeout as well.
    } else if (event.key == 'sessionStorage' && !sessionStorage.length) {
        // another tab sent data <- get it
        var data = JSON.parse(event.newValue);
        for (var key in data) {
            sessionStorage.setItem(key, data[key]);
        }
    }
};

// listen for changes to localStorage
if(window.addEventListener) {
    window.addEventListener("storage", sessionStorage_transfer, false);
} else {
    window.attachEvent("onstorage", sessionStorage_transfer);
};


// Ask other tabs for session storage (this is ONLY to trigger event)
if (!sessionStorage.length) {
    localStorage.setItem('getSessionStorage', 'foobar');
    localStorage.removeItem('getSessionStorage', 'foobar');
};