/**
* Renders the header (if any)
*
* @return null|string
*/
public function renderHeader()
{
if ($this->header !== false || !empty($this->header)) {
$content = ArrayHelper::getValue($this->header, 'label', '');
$options = ArrayHelper::getValue($this->header, 'options', ['class' => 'header']);
$header = Ui::tag('div', $content, $options);
$lines[] = Ui::beginTag('div', ['class' => 'content']);
$lines[] = $header;
return implode("\n", $lines);
} else {
return null;
}
}
