public function addPresForUser($usr_id)
{
// begin transaction
global $db;
$db->beginTransaction();
try {
Presentation::deletePresentationsByUserBySession($usr_id, $this->ses_id);
// Inserts the new session for the user.
$this->insert_presentation_for_user($usr_id);
if ($this->pres_paired_pres_id != null) {
$pairedPresentation = Presentation::getPresentation($this->pres_paired_pres_id);
// iterate through a change of presentation ids until we get back to where we started.
while ($pairedPresentation->pres_id != $this->pres_id) {
Presentation::deletePresentationsByUserBySession($usr_id, $pairedPresentation->ses_id);
// Inserts the new session for the user.
$pairedPresentation->insert_presentation_for_user($usr_id);
// iterate down the chain of paired presentations.
$pairedPresentation = Presentation::getPresentation($pairedPresentation->pres_paired_pres_id);
}
}
// commit transaction
$db->commit();
} catch (PDOException $e) {
// roll back transaction
$db->rollback();
// log any errors to file
log_pdo_exception($e, $usr_id, "Adding Presentation:" . $this, "addPresForUser");
display_error("Error saving data.");
exit;
}
}
