Javascript/HTML Storage Options Under File Protocol (file://)

I am developing an html application that is essentially a series of pages like a book. Within this application, I would like to store several JavaScript variables across pages. Think things like pages read, bookmarks, etc. When this application is viewed over HTTP, I plan to use localStorage with fallbacks for older browsers (globalStorage, userData, etc.).

H开发者_开发技巧owever, this completely breaks down if the files are accessed via "file://", for example if viewed off of a CD. It seems that most (if not all) localStorage solutions will not work under the file protocol. Cookies are not an option either under "file://".

Any ideas on how to persist JavaScript data across html pages when they are being viewed via "file://"?

It really only needs to be available in the current user session. I really don't want to use frames, but as of yet, I can't think of another way to accomplish this

A buddy of mine at work helped me out with this problem by sharing his implementation of using window.name to store data across pages of a single window/session.

A similar implementation (and discussion around the method) can be found here: http://ajaxian.com/archives/whats-in-a-windowname

Preliminary tests I've been doing on this method look very promising. I tested this, under the file protocol (loading page from desktop, a.k.a. - "file:\") on the following browsers. It worked on all of them!!

• IE 6
• IE 7
• IE 8
• IE 9
• FF 3.6
• FF 4
• Chrome 11
• Opera 10
• Safari 4

I have not yet done any testing as to how much data you can store here, but the internets seem to agree on a value of 2 MB.

Sources, links, more information

• JavaScript Programmer's Reference (Google Books)
• Cookie-less Session Variables in JavaScript - Sitepoint Article

On Webkit (Chromium 12.0.742.21 dev-m) localStorage over file protocol worked fine to me.

On Gecko it's reported and should be improved soon.

You can even find a workaround, but I recommend that you develop using Chrome nightly build. So you'll not lose time moving it back to localStorage in future.