Do not use double-colons in callbacks - Wikitech-l

4 Sep 2008

aaron(a)svn.wikimedia.org wrote:
...
   /**
 + * Additional functions to be performed with updateSpecialPages.
 + * Expensive Querypages are already updated.
 + */
 +$wgSpecialPageCacheUpdates = array(
 +	'Statistics' => 'SiteStatsUpdate::cacheUpdate'
 +);

This is the second time I've seen this, and I'm pretty sure it was from
two different authors.

DO NOT use a double-colon to specify calls to static functions!

Use an array instead: array( 'SiteStatsUpdate', 'cacheUpdate' )

Double-colons only work since 5.2.3, which means they may work during
development, but they will fail on some Wikimedia servers and on many
external installations.

The ONLY place where you should use a double-colon is in $wgHooks. We
had to use a double-colon in $wgHooks, with explode() to convert it to
an array, because arrays were already used for another purpose (passing
parameters).

-- Tim Starling