kartik\grid\ExpandRowColumn::getIcon PHP 메소드

    protected function getIcon($type)
    {
        $setting = "{$type}Icon";
        if (!empty($this->{$setting})) {
            return $this->{$setting};
        }
        $bs = $this->grid->bootstrap;
        if ($type === 'expand') {
            return $bs ? GridView::ICON_EXPAND : '+';
        }
        if ($type === 'collapse') {
            return $bs ? GridView::ICON_COLLAPSE : '-';
        }
        return null;
    }