Triggers are created on the command line with the new create-trigger command. This creates a topic of type Topincs trigger with id ID writes a file into STORE_DIR/php/triggers/ID.php. The user has to 1) specify when the trigger is run and 2) code what the trigger should do.

1) Specify: edit the trigger topic to specify which events the trigger is triggered by. Currently there is four events: name event, occurrence event, role event, and topic event. For each of those events a respective type has to be specified and at least one event type out of: before insert, before update, before delete, after insert, after update, after delete.

2) Code: the trigger is passed on execution the id of the topic in the variable $topic_id. From there he usually will get the Tobject and do whatever he needs to do, e.g. to calculate the duration of a works session:

$session = Tobject::get($topic_id);
if ($session->has_start() && $session->has_end()) {
  $session->set_duration($session->get_start()->diff($session->get_end());
}

When a work session in the issue store is finalized (the end date is set), the working time on the corresponding issue should be updated.

When an issue in the issues store is resolved (resolving date is set), the corresponding product version should be updated.