public function renderCellTemplate($columnName)
    {
        if ($columnName == 'attribute') {
            return $this->_getAttributeRenderer()
                ->setName($this->_getCellInputElementName($columnName))
                ->setTitle($columnName)
                ->setClass($this->className)
                ->setOptions(
                    $this->getElement()->getValues()
                )
                ->toHtml();
        } elseif ($columnName == 'conditions') {
            return $this->_getConditionsRenderer()
                ->setName($this->_getCellInputElementName($columnName))
                ->setTitle($columnName)
                ->setClass($this->className)
                ->setOptions(
                    $this->condition->toOptionArray()
                )
                ->toHtml();
        } elseif ($columnName == 'cvalue') {
            return $this->_getValueRenderer()
                ->setName($this->_getCellInputElementName($columnName))
                ->setTitle($columnName)
                ->setClass($this->className)
                ->setOptions(
                    $this->value->toOptionArray()
                )
                ->toHtml();
        }

        return parent::renderCellTemplate($columnName);
    }