FOF30\Model\TreeModel::getRoot PHP Метод

    public function getRoot()
    {
        // Empty node, let's try to get the first available root, ie lft=1
        if (!$this->getId()) {
            $this->load(array('lft' => 1));
        }
        // Sanity checks on current node position
        if ($this->lft >= $this->rgt) {
            throw new TreeInvalidLftRgtCurrent();
        }
        // If this is a root node return itself (there is no such thing as the root of a root node)
        if ($this->isRoot()) {
            return $this;
        }
        if (empty($this->treeRoot) || !is_object($this->treeRoot) || !$this->treeRoot instanceof TreeModel) {
            $this->treeRoot = null;
            // First try to get the record with the minimum ID
            $db = $this->getDbo();
            $fldLft = $db->qn($this->getFieldAlias('lft'));
            $fldRgt = $db->qn($this->getFieldAlias('rgt'));
            $subQuery = $db->getQuery(true)->select('MIN(' . $fldLft . ')')->from($db->qn($this->tableName));
            try {
                $root = $this->getClone()->reset()->whereRaw($fldLft . ' = (' . (string) $subQuery . ')')->firstOrFail();
                if ($this->isDescendantOf($root)) {
                    $this->treeRoot = $root;
                }
            } catch (\RuntimeException $e) {
                // If there is no root found throw an exception. Basically: your table is FUBAR.
                throw new TreeRootNotFound($this->tableName, $this->lft);
            }
            // If the above method didn't work, get all roots and select the one with the appropriate lft/rgt values
            if (is_null($this->treeRoot)) {
                // Find the node with depth = 0, lft < our lft and rgt > our right. That's our root node.
                $query = $db->getQuery(true)->select(array($db->qn('node') . '.' . $fldLft, '(COUNT(' . $db->qn('parent') . '.' . $fldLft . ') - 1) AS ' . $db->qn('depth')))->from($db->qn($this->tableName) . ' AS ' . $db->qn('node'))->join('CROSS', $db->qn($this->tableName) . ' AS ' . $db->qn('parent'))->where($db->qn('node') . '.' . $fldLft . ' >= ' . $db->qn('parent') . '.' . $fldLft)->where($db->qn('node') . '.' . $fldLft . ' <= ' . $db->qn('parent') . '.' . $fldRgt)->where($db->qn('node') . '.' . $fldLft . ' < ' . $db->q($this->lft))->where($db->qn('node') . '.' . $fldRgt . ' > ' . $db->q($this->rgt))->having($db->qn('depth') . ' = ' . $db->q(0))->group($db->qn('node') . '.' . $fldLft);
                // Get the lft value
                $targetLeft = $db->setQuery($query)->loadResult();
                if (empty($targetLeft)) {
                    // If there is no root found throw an exception. Basically: your table is FUBAR.
                    throw new TreeRootNotFound($this->tableName, $this->lft);
                }
                try {
                    $this->treeRoot = $this->getClone()->reset()->whereRaw($fldLft . ' = ' . $db->q($targetLeft))->firstOrFail();
                } catch (\RuntimeException $e) {
                    // If there is no root found throw an exception. Basically: your table is FUBAR.
                    throw new TreeRootNotFound($this->tableName, $this->lft);
                }
            }
        }
        return $this->treeRoot;
    }