[pmwiki-users] Arbitrary filtering for (:pagelist:) - is there a better way?

[Michael Tempest]

Hi

I have pages in my PmWiki that are applicable to a specific date, like a 
calendar. I've encoded the data in the name (for example "Event-2006-07-13"), 
which lets me order by name (or -name) and the pages are ordered by date. (I 
can't use creation date or last-modified date - these pages may be created in 
any order and will often be modified after the applicable date.)

So far, it works without a problem.

I want to list pages for future dates or for past dates. I cannot think of a 
regular expression that would let me do that - I think actual code is 
necessary.

I added a "filter" option to MakePageList() in pagelist.php, configured with a 
new global called $SearchFilterFunctions. Here is the modification to 
MakePageList():
    ....
    if (@$opt['trail']) {
    ...
    } else $list = ListPages($pats);

>    if (@$opt['filter']) {
>        if (function_exists(@$SearchFilterFunctions[$opt['filter']])) {
>            $list = $SearchFilterFunctions[$opt['filter']]($list);
>        }
>    }

    if (IsEnabled($EnablePageListProtect, 1)) $readf = 1000;
    $matches = array();
    $FmtV['$MatchSearched'] = count($list);
    ....

Here is an example of how I use it (from config.php):
  # This is accessible as (:pagelist filter=future:)
  $SearchFilterFunctions['future'] = 'SearchFilterFuture';
  function SearchFilterFuture(&$input_list)
  {
      $output_list = array();
      foreach ($input_list  as $page)
      {
          if (preg_match('/(\d\d\d\d-\d\d-\d\d)/', $page, $matches))
          {
              $event_date = $matches[1];
              $today = date("Y-m-d");
              if ($event_date >= $today)
              {
                  $output_list[] = $page;
              }
          }
          else
          {
              $output_list[] = $page;
          }
      }
      return $output_list;
    }

This all works. My question is - is there a better way?

1) Is there a way to do with without modifying pagelist.php?

2) I'm not very familiar with php's array functions (in fact, PmWiki is my 
first encounter with php), so is there a better way to reduce the list than 
"$list = $SearchFilterFunctions[$opt['filter']]($list);" ?

3) I've not been working with (:pagelist:) for very long. As a generalisation, 
is it better to be inclusive or exclusive with pagelists and the like? I've 
chosen to include pages that don't match the desired form. Would it be better 
to exclude them?

Have a great day

Michael