[Mediawiki-l] "Refreshing" a category page via MediaWiki program calls

[Hugh Prior]

I have a page Alpha, which contains a "Category: X" link, but the "Category: 
X" page does not have the page Alpha listed on it.  When I edit the page 
Alpha then the "Category: X" page correctly lists the Alpha page.  My 
question: how can I force, with MediaWiki calls, an update of the category 
links.  I have tried with the following code to even check if the category 
links are OK, but this does not seem to work.  Thanks for any ideas.

$pageName = "Alpha";
$title = new Title();
$title = $title->newFromText($pageName);

$linkCache = new LinkCache();
$linkCache->preFill($title);

$catLinks = $linkCache->getCategoryLinks();

print_r($catLinks, "catLinks");