Admin_DocumentController::treeGetChildsByIdAction PHP Method

    public function treeGetChildsByIdAction()
    {
        $document = Document::getById($this->getParam("node"));
        $documents = [];
        $cv = false;
        if ($document->hasChilds()) {
            $limit = intval($this->getParam("limit"));
            if (!$this->getParam("limit")) {
                $limit = 100000000;
            }
            $offset = intval($this->getParam("start"));
            if ($this->getParam("view")) {
                $cv = \Pimcore\Model\Element\Service::getCustomViewById($this->getParam("view"));
            }
            $list = new Document\Listing();
            if ($this->getUser()->isAdmin()) {
                $list->setCondition("parentId = ? ", $document->getId());
            } else {
                $userIds = $this->getUser()->getRoles();
                $userIds[] = $this->getUser()->getId();
                $list->setCondition("parentId = ? and\n                                        (\n                                        (select list from users_workspaces_document where userId in (" . implode(',', $userIds) . ") and LOCATE(CONCAT(path,`key`),cpath)=1  ORDER BY LENGTH(cpath) DESC LIMIT 1)=1\n                                        or\n                                        (select list from users_workspaces_document where userId in (" . implode(',', $userIds) . ") and LOCATE(cpath,CONCAT(path,`key`))=1  ORDER BY LENGTH(cpath) DESC LIMIT 1)=1\n                                        )", $document->getId());
            }
            $list->setOrderKey(["index", "id"]);
            $list->setOrder(["asc", "asc"]);
            $list->setLimit($limit);
            $list->setOffset($offset);
            \Pimcore\Model\Element\Service::addTreeFilterJoins($cv, $list);
            $childsList = $list->load();
            foreach ($childsList as $childDocument) {
                // only display document if listing is allowed for the current user
                if ($childDocument->isAllowed("list")) {
                    $documents[] = $this->getTreeNodeConfig($childDocument);
                }
            }
        }
        if ($this->getParam("limit")) {
            $this->_helper->json(["offset" => $offset, "limit" => $limit, "total" => $document->getChildAmount($this->getUser()), "nodes" => $documents]);
        } else {
            $this->_helper->json($documents);
        }
        $this->_helper->json(false);
    }