/**
* Add special filtering of tasks by categories.
* @param array<mixed> $filter two dimensional array of category IDs, it is represented as logic formula in conjunctive normal form, where first dimension is clause and second is disjunct inside clause.
*/
public function add_categories_filter($filter)
{
$select_subquery = ' ( SELECT `cat_tasks`.`id` FROM `tasks` `cat_tasks` ';
$where_part = '';
if (count($filter) > 0) {
$clause = 0;
/*echo '<pre>';
print_r($filter);
echo '</pre>';*/
foreach ($filter as $cats) {
if (count($cats) > 0) {
$where_part .= (!empty($where_part) ? ' AND ' : '') . ' ( ';
$or_where_part = '';
$category = FALSE;
$task_set = FALSE;
foreach ($cats as $cat) {
if (substr($cat, 0, 9) == 'category:') {
if (!$category) {
$select_subquery .= ' LEFT OUTER JOIN `task_category_rel` `categories_' . $clause . '` ON `cat_tasks`.`id` = `categories_' . $clause . '`.`task_id` ';
$category = TRUE;
}
$category = new Category();
$id_list = $category->get_id_list(intval(substr($cat, 9)));
$or_where_part .= (!empty($or_where_part) ? ' OR ' : '') . '`categories_' . $clause . '`.`category_id` IN (' . implode(', ', $id_list) . ') ';
} else {
if (substr($cat, 0, 7) == 'course:') {
if (!$task_set) {
$select_subquery .= ' LEFT OUTER JOIN `task_task_set_rel` `task_rel_' . $clause . '` ON `cat_tasks`.`id` = `task_rel_' . $clause . '`.`task_id` ';
$select_subquery .= ' LEFT OUTER JOIN `task_sets` `task_set_' . $clause . '` ON `task_rel_' . $clause . '`.`task_set_id` = `task_set_' . $clause . '`.`id` ';
$task_set = TRUE;
}
$or_where_part .= (!empty($or_where_part) ? ' OR ' : '') . '`task_set_' . $clause . '`.`course_id` = ' . intval(substr($cat, 7));
}
}
}
$where_part .= $or_where_part . ' ) ';
$clause++;
}
}
}
$where_part .= (!empty($where_part) ? ' AND ' : '') . ' `tasks`.`id` = `cat_tasks`.`id` ';
$select_subquery .= ' WHERE ' . $where_part . ' GROUP BY `cat_tasks`.`id` ) ';
$this->db->ar_where[] = ' EXISTS ' . $select_subquery;
//echo ' EXISTS ' . $select_subquery;
}
