[Pmwiki-users] Add a date/time option for viewing an old version of a page

[Patrick R. Michaud]

On Sat, Dec 11, 2004 at 11:09:46PM +0100, chr at home.se wrote:
> Here's an idea for a feature which I've found that I'd like to have.
> I'd like to be able to see a page as it appeared on a given date/time, and
> ideally all page links would then also go to pages at that date/time.

This is PITS:00220 -- cast your vote there.  :-)

> For instance, I'd like the URI
> 	http://www.pmwiki.org/Group/Page?time=20:03
> to show me the page as it appeared at 20:03 today, and I'd like
> 	http://www.pmwiki.org/Group/Page?time=20:03&date=2004-12-01
> to show me the page as it appeared at 2004-12-01 20:03. Ideally these 
> parameters would be sticky, so links to other pages would automatically 
> get 'time=..&date=...' appended to their URIs.

I hadn't thought of making them sticky -- that's worth thinking about
(and placing a note in the pits entry).  Plus I think there should be 
a way to specify both date and time in a single parameter -- i.e.,  

    when=2004-12-01+20:03
    when=2004-12-01
    when=20:03
    when=12-01+20:03

It might even be worth looking at accepting several date/time formats
(e.g., from any standard date/time parsing that PHP provides), or formats
in a variety of standards.

A question:  what do we do if the requested date is
prior to a page's available a history (i.e., if the relevant diffs
have expired)?  What if the expiration dates are different between
pages, does the "stickiness" of the date change at all?

> Does this sound like something useful?  Would it be supported by the 
> current (pmwiki2) implementation of how pages/diffs are stored?

Sure, technically it's fairly easy to achieve, although there are going
to be a few quirks here and there.  For example, we won't have a way to
view deleted pages, and links to pages that didn't exist in the past
would show up as existing (although following the page link would 
display "Describe {$FullName} here" for the target page's text).

And no, I don't have any present plans to make PmWiki into a full-fledged
version control system (i.e., being able to recover deleted pages).

Pm