CiviCRM Community Forums (archive)

Hello,
I want to output participant id in email tamplate, after some research found that need to extend Event\BAO\Event.php and add $sendTemplateParams['tplParams']['participantID'] = $participantId;
What is safest way to extend it?
Also there problem: For example If somebody ordered 2 tickets then in email of main participant id is 0 but in email of additional participant there right id. How to fix this problem? Thank you