The CategoryTree extension is already included as a standard in wikis of the biowikifarm and usually does not require installation. However, it can be usefull to change the settings of the extension like the level of depth in which a category tree is displayed. For details on its use and its settings see the respective Wikimedia page.
The depth level for displaying category trees depends on the mode, it is normally set to:
- 2 levels for mode=categories (default)
- 1 level for all other modes.
The depth level can be changed by adding a line to LocalSettings.php, e.g.
$wgCategoryTreeMaxDepth = array(CT_MODE_PAGES => 2, CT_MODE_ALL => 2, CT_MODE_CATEGORIES => 3, CT_MODE_PARENTS => 5);
near the end of the file would increase the depth levels to:
- 3 levels for mode=categories
- 5 levels for mode=parents
- 2 levels for other modes.