Re: [WWdevel] webwork page caching

[Sam H. <sh...@ma...>]

On Nov 2, 2005, at 11:34, P Gavin LaRose wrote:

> Hi all,
>
> Watching some of our gateway testing, the following occurred to me:  
> it would be good to avoid students being able to use the browser's  
> "back" button to navigate.  And then I thought that this should be  
> a desirable state of affairs in general.  Because WeBWorK pages  
> contain state data, we don't really want people going back to  
> previous pages.  I use this occasionally when I'm working as a  
> course administrator, but on student pages I think it's something  
> we don't want happening.
>
> Would it make sense to add a 'no-cache' command to the header of  
> all WeBWorK pages, so that it would force the browser to go back to  
> the server to get each new page?

Is the problem just that there could be out-of-date information on  
cached pages? (Like the case where a user attempts a problem for the  
first time and then hits back to return to the problem list and it  
tells her that she hasn't attempted it?) Or are there more dangerous  
cases? (If there are those should be removed regardless of whether we  
add no-cache.)

I actually like being able to quickly pop back to the previous page  
and then forward to the current one one without reloading.

If we added no-cache we would also want to be more careful about when  
we use POST versus GET. Good browsers warn you when a POST request  
needs to be resubmitted (like in the case of no-cache) and this is  
annoying when the re-POST isn't actually dangerous.
-sam