Where should custom "Region" calls be stored?

Question

I'm wanting to add content to a region in EventInfo.tpl. The Docs give this function as an example, but do not clarify exactly where this "CRM_Core_Region::instance('page-body')->add" method is called from.

  CRM_Core_Region::instance('page-body')->add(array(
      'markup' => '<p>Congratulations! You won the lottery!</p>',
  ));

Can I call this method from within a theme file like functions.php? Is there a predefined directory where custom region code should live?

Answer 1

You need to implement it in hook, if you are looking to add content on event info page than you will need to implement it in pageRun() hook

Answer 2

Solution found: https://docs.civicrm.org/dev/en/latest/hooks/usage/wordpress/

add_filter('civicrm_pageRun', 'addJoinLink', 10, 4 );

function addJoinLink() {
    CRM_Core_Region::instance('event-page-eventinfo-actionlinks-top')->add(array(
        'markup' => '<p>Congratulations! You won the lottery!</p>',
    ));
}