After installing this plugin, any users who access your site with MS IE 6 will at first see a page explaining that they are using old technology and offer links to download newer better browsers.

The user has the option to click-through to view your site anyway, with the caveat it may not work properly.

Finally, this warning page is only shown to the user once per server session. This way there is no extra cookie overhead, no database overhead to store the setting, and the added bonus that if their session expires they will see the warning once again - re-inforcing the fact that they need to upgrade!

This plugin is primarily intended for use during development when you haven't yet endured the world of pain that is backporting your site to what is probably the world's biggest waste of investment and effort in IT.

The page shown to users

The warning page has basic self-contained styling and links to all the major high quality browsers ("ooops", MS IE not included...) and renders well in MS IE6, as that's the only people who will see it. You can probably override this page by creating a new "grails-app/views/lamers/get-a-real-browser.gsp" view in your application.

Thanks to http://twitter.com/seb_grant for the page styling.

Testing it

To test, simply use MSIE6 … or if you actually have a better browser, use the debug tools to set the user agent to MS IE 6. Load any page on the site and you will see the warning. But remember that reloading the page in that sessions will bypass the filter...

Performance

This plugin currently uses a Grails filter to intercept all requests. The code path is very short for non-IE6 users so this should not have a major impact on performance, but converting it to be a Java filter may be better in future (contribs welcome). However, I don't really recommend blocking MS IE6 users in this way from most apps - but it is certainly useful during beta/development when you haven't begun the dreadful process of trying to make it work/look OK in MS IE6.