kartik\grid\RadioColumn::renderHeaderCellContent PHP 메소드

    protected function renderHeaderCellContent()
    {
        if ($this->header !== null || !$this->showClear) {
            return parent::renderHeaderCellContent();
        } else {
            $label = ArrayHelper::remove($this->clearOptions, 'label', '×');
            Html::addCssClass($this->clearOptions, 'kv-clear-radio');
            if (empty($this->clearOptions['title'])) {
                $this->clearOptions['title'] = Yii::t('kvgrid', 'Clear selection');
            }
            $this->_view->registerJs("kvClearRadio({$this->_clientVars});");
            return Html::button($label, $this->clearOptions);
        }
    }