mybb_get-pmid.txt

$plugins->add_hook('datahandler_pm_insert', 'pm_insert');
$plugins->add_hook('private_do_send_end', 'pm_private_end');

function pm_insert($handler)
{
	global $cache;
	static $last_uid;

	if(!isset($cache->cache['pmcache']))
	{
		// Hijack the cache for our dastardly plan
		$cache->cache['pmcache'] = array();
	}

	if(!empty($handler->pmid))
	{
		// Update the PMID for the last user
		$cache->cache['pmcache'][$last_uid] = array('uid' => $last_uid, 'pmid' => $handler->pmid);
	}

	$last_uid = $handler->pm_insert_data['toid'];
}

function pm_private_end()
{
	global $mybb, $pmhandler;

	// pm_insert doesn't handle the last recipient but we still have the data; update it.
	$pm = $pmhandler->pm_insert_data;
	$pmcache = $mybb->cache->read('pmcache');
	$pmcache[$pm['toid']] = array('user' => $pm['toid'], 'pmid' => $pmhandler->pmid);

	// $pmcache now contains all recipients and their respective PMIDs
	print_r($pmcache);
	die;
}