CLearnLessonTree::__construct

public function __construct ($rootLessonId, $arOrder = null, $arFilter = array(), $publishProhibitionMode = true, $arSelectFields = array())
{
	$this->EnsureStrictlyCastableToInt ($rootLessonId);		// throws an exception on error
	if ($arOrder === null)
		$arOrder = array ('EDGE_SORT' => 'asc');

	if (is_array($arSelectFields) && (count($arSelectFields) > 0))
	{
		$arFieldsMustBeSelected = array ('LESSON_ID', 'EDGE_SORT', 'IS_CHILDS');
		foreach ($arFieldsMustBeSelected as $fieldName)
		{
			if ( ! in_array($fieldName, $arSelectFields) )
				$arSelectFields[] = $fieldName;
		}
	}

	$publishProhibitionContext = false;

	if ($publishProhibitionMode)
	{
		$publishProhibitionContext = (int) $rootLessonId;

		global $DB;
		$rc = $DB->Query (
			"SELECT PROHIBITED_LESSON_ID
			FROM b_learn_publish_prohibition
			WHERE COURSE_LESSON_ID = $publishProhibitionContext",
			true	// ignore errors
			);

		if ($rc === false)
			throw new LearnException ('EA_SQLERROR', LearnException::EXC_ERR_ALL_GIVEUP);

		while ($arData = $rc->Fetch())
			$this->arPublishProhibitedLessons[] = (int) $arData['PROHIBITED_LESSON_ID'];
	}

	$arCurrentPath = array($rootLessonId);
	$this->arTree = $this->BuildTreeRecursive(
		$rootLessonId, 
		$arOrder, 
		$arFilter, 
		0, 
		NULL, 
		$arSelectFields, 
		$arCurrentPath
	);
}