/**
* Renders the content to be inserted in the head section.
* The content is rendered using the registered meta tags, link tags, CSS/JS code blocks and files.
*
* @return string the rendered content
*/
protected function renderHeadHtml()
{
$lines = [];
$lines[] = $this->head;
$lines[] = '<head>';
$lines[] = Html::tag('title', $this->title);
if (!empty($this->metaTags)) {
$lines[] = implode("\n", $this->metaTags);
}
if (!empty($this->linkTags)) {
$lines[] = implode("\n", $this->linkTags);
}
if (!empty($this->cssFiles[self::POS_HEAD])) {
$lines[] = implode("\n", $this->cssFiles[self::POS_HEAD]);
}
if (!empty($this->css)) {
$lines[] = implode("\n", $this->css);
}
if (!empty($this->jsFiles[self::POS_HEAD])) {
$lines[] = implode("\n", $this->jsFiles[self::POS_HEAD]);
}
if (!empty($this->js[self::POS_HEAD])) {
$lines[] = Html::script(implode("\n", $this->js[self::POS_HEAD]), ['type' => 'text/javascript']);
}
$lines[] = '</head>';
return empty($lines) ? '' : implode("\n", $lines);
}
