Task::getUserInfo

static function getUserInfo($userId, $needFullName = true)
{
	static $users = array();

	if (!array_key_exists($userId, $users))
	{
		$select = array('ID', 'PERSONAL_PHOTO', 'NAME', 'LAST_NAME', 'SECOND_NAME', 'EXTERNAL_AUTH_ID');
		if (Loader::includeModule('crm'))
		{
			$select[] = 'UF_USER_CRM_ENTITY';
		}
		$res = BitrixMainUserTable::getList(
			array(
				'select' => $select,
				'filter' => array(
					'ID' => $userId
				)
			)
		);
		$user = (array)$res->fetch();

		$site = BitrixTasksUtilSite::get(SITE_ID);
		$siteId = $site["SITE_ID"];

		$users[$userId] = array(
			'ID' => $user['ID'],
			'NAME' => htmlspecialcharsbx(UtilUser::formatName($user, $siteId)),
			'AVATAR' => BitrixTasksUI::getAvatar($user['PERSONAL_PHOTO'], 100, 100),
			'IS_EXTERNAL' => BitrixTasksUtilUser::isExternalUser($user['ID']),
			'IS_CRM' => array_key_exists('UF_USER_CRM_ENTITY', $user) && !empty($user['UF_USER_CRM_ENTITY'])
		);

	}

	return $users[$userId];
}