AFTER action is never performed on a successful
The passed Doku_Event has the field
$data is a string or array containing the $ACT value (the
do variable in the query string - uncleaned). See act_clean() for an example of cleaning.
Add a BEFORE event handler to process your action. Check the
$data field for the correct action name. Also use an unique action name to avoid collisions.
preventDefault() to skip DokuWiki's processing of the action.
$data is a reference to the $ACT variable, so assigning another action string to the
$data field will be noticed outside your event handler.
The AFTER event handler lets you handle actions after performing DokuWiki's default action handling (attention: can be eventually skipped by
preventDefault()) . Due to handling of actions by plugins and DokuWiki itself the AFTER event handler can be reached with another action than you expect at first sight. Please be aware it.
The following plugins are known to handle this event and their source code may be a good start for understanding and implementing a handler yourself.