How can I enable cached offline access to a web app in IE8 with LocalStorage support?

Question

I am currently producing a web application which has a hard requirement on IE8 support. The application has to store data to LocalStorage when the user is online, and allow the page to be cached in the event that the user is offline.

When the user is offline, this LocalStorage data is used to populate views and support the process.

The current process is that the application can allow access online, and should cache specific resources, and operate with purely HTML / CSS / JS while offline, even if the user closes and opens the page back up.

Normally I could use the offline manifest, but this is unsupported in IE8.

This page is almost helpful, except that the person gave up on ever supporting IE8: http://dotnetflare.wordpress.com/2012/08/06/offline-html5-application-vs-ie8/

Google Gears is not preferred as it is deprecated and the web application will be operating in a locked down IT environment where it may not be possible to install plugins. That said, I appreciate if there are other plugins that may support this function (does Chrome Frame add offline manifest support?).

I also can't just use an offline saved copy of the site, as this will not support the LocalStorage of the online copy as they will not be on the same domain.

What are my options here?

Answer 1

As per here, you can use the File -> Work Offline capability in IE8 to simulate running from the cache as you would with a cache manifest. From here your code can use the LocalStorage and offline detection as normal.

At the end of the day we decided to convince the client to run Chrome Frame despite its phasing out, but this was helpful in developing a PoC.