Ability to write rules in PHP and test them

I needed more complex autoaliasing rules than the current template allows and hence decided to write support for using PHP scripts to generate them. The attached patch describes these changes against version 4.5.0.

It also adds a few new options:

• Enabled: Activate/disable automatic aliasing of new nodes. It is a good idea to keep this unchecked while trying out different naming schemes.
• Add only missing: Add aliases only if there are no aliases already? Note that you could do this check manually in PHP even if you answer 'no' here.
• Test rules (below the "mass update checkbox"):Test the rules against all existing nodes. This only shows a list of generated aliases without actually adding any.

I don't know if this makes the module too complicated for your taste but I definitely needed this functionality so here it is.

As an example for the scripts, this is more or less what I currently use for effi.org's experimental Drupal site and it works like charm:

// Shorten the title if necessary and try to respect word boundaries
$title = preg_replace('/^EFFI:[ ]*/','',$node->title);
$title = strtolower(clean_alias($title));
$title = preg_replace('/^([a-z0-9-]{16,28})[^a-z0-9].*$/', '$1', $title);
$title = substr($title,0,28);

// The actual rules
if ( $node->type == "blog" )
  $res[] = "blog/" . clean_alias( "$yyyy-$mm-$dd-" .$node->name).".html";
else if ( $node->type == "story" )
  $res[] = "news/" . clean_alias( "$yy$mm$dd-" .$title) . ".html";
else
{
  if (isset($taxotree["Publication type"]["Press releases"])) 
    $res[] = "publications/releases/press-release". "-$yyyy-$mm-$dd.html";
  else if ( isset($taxopaths["Publication type"]))
    $res[] = clean_alias(strtolower( 
      $taxopaths["Publication type"][0]), '/') .'/' .$title . "-$yy$mm$dd.html";
  else if ( isset($taxotree["Activity theme"]) ||
      isset($taxotree["Publication type"]) )
  $res[] = strtolower($catpath . $title) . '.html';
}