Extension:GeoCrumbs

Installation
You also need to install:
 * Extension:CustomData

To install this extension, add the following to LocalSettings.php:

How it works
This extension provides a new MediaWiki function named "isin". It expects one argument, the name of the article where the current article "is in".

During parsing of the wiki markup, some few data related to the isin function's argument are generated and stored in the parser cache.

When the article is displayed, it's HTML code has to be build from the parser cache. The BreadCrumbs extension has a method triggered by the 'SkinTemplateOutputPageBeforeExec' hook. Here, the complete bread crumb trail is build up by starting with the article's own isin and retrieving subsequently higher level isin data from the corresponding parser caches. The HTML code of the bread crumb trail is added to the page's subtitle.

Feedback
Open tickets in Wikimedia's Bugzilla under the "GeoCrumbs" component in the "MediaWiki extensions" product.
 * Open GeoCrumbs tickets