/**
* Get the previous lesson in row, or in the course, if specified
*
* @param EfrontLesson $lesson The lesson to account
* @param mixed $course The course to regard, or false
* @return int The id of the previous lesson in row
* @since 3.6.3
* @access public
*/
public function getPreviousLesson($lesson, $course = false)
{
$previousLesson = false;
if ($course) {
$course instanceof EfrontCourse or $course = new EfrontCourse($course);
$eligibility = new ArrayIterator($course->checkRules($_SESSION['s_login']));
while ($eligibility->valid() && ($key = $eligibility->key()) != $lesson->lesson['id']) {
$previous = $key;
$eligibility->next();
}
if (isset($previous) && $previous) {
$previousLesson = $previous;
}
} else {
$directionsTree = new EfrontDirectionsTree();
$userLessons = new ArrayIterator($directionsTree->getLessonsList($this->getUserLessons()));
while ($userLessons->valid() && ($key = $userLessons->current()) != $lesson->lesson['id']) {
$previous = $key;
$userLessons->next();
}
if (isset($previous) && $previous) {
$previousLesson = $previous;
}
}
return $previousLesson;
}
