protected function getExtraButtons($index, $item)
    {
        if (!$this->extraButtons) {
            return '';
        }

        if (is_callable($this->extraButtons)) {
            $content = call_user_func($this->extraButtons, $item, $index, $this->context);
        } else {
            $content = $this->extraButtons;
        }

        if (!is_string($content)) {
            throw new InvalidParamException('Property "extraButtons" must return string.');
        }

        return $content;
    }
protected function getExtraButtons($index, $item)
    {
        if (!$this->extraButtons) {
            return '';
        }

        if (is_callable($this->extraButtons)) {
            $content = call_user_func($this->extraButtons, $item, $index, $this->context);
        } else {
            $content = $this->extraButtons;
        }

        if (!is_string($content)) {
            throw new InvalidParamException('Property "extraButtons" must return string.');
        }

        return $content;
    }
protected function getExtraButtons ( $ index , $ item ) { if ( ! $ this -> extraButtons ) { return '' ; } if ( is_callable ( $ this -> extraButtons ) ) { $ content = call_user_func ( $ this -> extraButtons , $ item , $ index , $ this -> context ) ; } else { $ content = $ this -> extraButtons ; } if ( ! is_string ( $ content ) ) { throw new InvalidParamException ( 'Property "extraButtons" must return string.' ) ; } return $ content ; }
Render extra content in action column.

@param $index
@param $item

@return string
Render extra content in action column .