Feature idea: I'd like to be able to tag pages in an ikiwiki blog with a
publication date, and have the option of building a blog that excludes
publication dates in the future.  (meta pubdate= ?)

I'm using ikiwiki on git for a "tip of the day" RSS feed, and I'd like to
be able to queue up a bunch of items instead of literally putting in one
tip per day.  In the future I think this will come in handy for other
Mainstream Media-oriented requirements such as "embargo dates" and "editor
on vacation".

> The problem with implementing a feature like this is that, since ikwiiki
> is a wiki compiler, if something causes content to change based on the
> date, then the wiki needs to be rebuilt periodically. So you'd need a
> cron job or something.
>
> Thinking about this some more, if you're going to have a cron job, you
> could just set up a branch containing the future post. The branch could
> have a name like 20080911. Then have the cron job git merge the day's
> branch, if any, into master each day. And voila, post is completly hidden
> until published. You'd want to avoid merge conflicts in your cron job ..
> but they'd be unlikely if you limited yourself to just adding new
> pages. Alternatively, for larger organisations wishing to deploy more
> sweeping changes on a given date, replace cron job with intern.. ;-)
> --[[Joey]]

> > Good approach if you have one day on which a big change goes through, but
> > often the reason for tagging with a publication date is so that you can
> > dribble out articles one per day when you're gone for a week.  Branches are easy
> > in git, but it would still be an extra step to switch branches every time
> > you edit a different day's article.
> >
> > And just to make it a little harder, some sites might want an internal 
> > copy of the wiki that _does_ build the future pages, just tags them with the publication
> > date, for previewing.
> > 
> > One more reason to have publication date: if you move a page from your old CMS to ikiwiki
> > and want to have it show up in the right order in RSS feeds.
> >
> > I no longer have the original wiki for which I wanted this feature, but I can
> > see using it on future ones. -- [[DonMarti]]

>>> FWIW, for the case where one wants to update a site offline,
>>> using an ikiwiki instance on a laptop, and include some deffered
>>> posts in the push, the ad-hoc cron job type approach will be annoying.
>>> 
>>> In modern ikiwiki, I guess the way to accomplish this would be to
>>> add a pagespec that matches only pages posted in the present or past.
>>> Then a page can have its post date set to the future, using meta date,
>>> and only show up when its post date rolls around.
>>> 
>>> Ikiwiki will need to somehow notice that a pagespec began matching
>>> a page it did not match previously, despite said page not actually
>>> changing. I'm not sure what the best way is. 
>>>
>>> * One way could be to 
>>>   use a needsbuild hook and some stored data about which pagespecs
>>>   exclude pages in the future. (But I'm not sure how evaluating the
>>>   pagespec could lead to that metadata and hook being set up.) 
>>> * Another way would be to use an explicit directive to delay a
>>>   page being posted. Then the directive stores the metadata and
>>>   sets up the needsbuild hook.
>>> * Another way would be for ikiwiki to remember the last 
>>>   time it ran. It could then easily find pages that have a post
>>>   date after that time, and treat them the same as it treats actually
>>>   modified files.  Or a plugin could do this via a needsbuild hook,
>>>   probably. (Only downside to this is it would probably need to do
>>>   a O(n) walk of the list of pages -- but only running an integer
>>>   compare per page.)
>>> 
>>> You'd still need a cron job to run ikiwiki -refresh every hour, or
>>> whatever, so it can update. --[[Joey]] 
