Hook listeners

Hooks are invoked by the core code as $hooks->cat('action'); (replace action as appropriate). To respond, a hook listens for the action to be called. This is sometimes called a Publish/Subscribe model. The listener functions are the subscribers. And each call or generate publishes to all subscribers.

File-based hooks do this with methods named listen_action (again replace action with the actual label). E.g. a file-based system hook would be listen_startApplication. A database hook listens for the defined hooks_action.

You may need to say $hooks, $GLOBALS['hooks'], $admin_hooks, or $GLOBALS['admin_hooks'] depending on where you are.

In admin, each action has an associated hook. I.e. each file in admin/includes/actions/page_name/*.php has an action with the file name converted to a hook name. E.g. admin/includes/actions/manufacturers/insert.php would be listen_insertAction and accessed from a URL admin/manufacturers.php?action=insert (or whatever name your admin folder uses). The action is defined as a GET parameter, even though most of them must be invoked by form POST.

See also

Hooks