/**
  * render cell template.
  *
  * @param string $columnName
  *
  * @return string
  */
 public function renderCellTemplate($columnName)
 {
     if ($columnName == 'attribute') {
         return $this->_getAttributeRenderer()->setName($this->_getCellInputElementName($columnName))->setTitle($columnName)->setExtraParams('style="width:160px"')->setOptions($this->getElement()->getValues())->toHtml();
     } elseif ($columnName == 'conditions') {
         return $this->_getConditionsRenderer()->setName($this->_getCellInputElementName($columnName))->setTitle($columnName)->setExtraParams('style="width:160px"')->setOptions($this->condition->toOptionArray())->toHtml();
     } elseif ($columnName == 'cvalue') {
         return $this->_getValueRenderer()->setName($this->_getCellInputElementName($columnName))->setTitle($columnName)->setExtraParams('style="width:160px"')->setOptions($this->value->toOptionArray())->toHtml();
     }
     return parent::renderCellTemplate($columnName);
 }