[pmwiki-devel] markup order for group headers

[Patrick R. Michaud]

On Mon, Jan 29, 2007 at 06:43:29PM -0000, marc wrote:
> Patrick R. Michaud said...
> > If you're talking about the GroupHeader pages, then no, they're
> > run at the same time as page's markup.  In fact, GroupHeader effectively
> > works by adding the equivalent of
> >     (:include GroupHeader:)(:nl:)
> > to the beginning of the page text before processing the markup.
> > (The actual text to be prepended is given by $GroupHeaderFmt.)
> 
> So, say, in GroupHeader I have
> 
>   (:auxselectdata test2 1 2 3':)
>   (:auxSelect test2 test2 text='GroupHeader: ':)
> 
> The first markup basically does:
> 
>   $AuxSelectData[test2] = array(1,2,3);
> 
> while the second displays the dropdown, populated with $AuxSelectData
> [test2]
> 
> That works (in the GroupHeader) and displays above page text, as normal.
> 
> Now, when I add the same markup to the page (but use, say   
> (:auxselectdata test2 4 5 6':) to distinguish it), ...

How is this second one "distinguished" from the first?  To me they
look as though they are both doing the same thing -- i.e., setting
values for $AuxSelectData.

> the function the 
> markup calls issues an error stating that an existing array cannot be 
> overwritten (I do this as a security measure). But the error is raised 
> within the GroupHeader. This is confirmed by the fact that both the 
> dropdown on the page and in the header contain the population data from 
> the page - 4,5,6 in this case.

What's the value of the $when parameter that is being used
for the (:auxselectdata:) markup?  That's critically important here.

> I can extend this to include SiteHeader and exactly the same thing 
> happens.
> 
> IOW, the function called by (:auxselectdata:) in the page is being 
> called before both the Group and Site headers.

It's a mistake to assume that PmWiki processes pages and headers 
separately.  What happens is that the Group and Site headers are 
inserted into the text of the page (via (:include:)) as the page 
is being processed.  

So, if all of the (:auxselectdata:) directives
are being processed before any of the (:input:) directives, 
then each (:input:) directive is simply seeing the results of
the last (:auxselectdata:) directive encountered (i.e., the one
that is in the page, which replaced any values set by the ones
in the Group and Site).

And if the (:auxselectdata:) directive is processed before
(:include:) directives are processed, then yes, the page's values
will be evaluated first, followed by the group and site values.

So, it all comes back to the question of when the (:auxselectdata:)
markup is being processed in relation to the other (:input:) markups
(and possibly the (:include:) markups as well).

Pm