/**
* Parse string into DOMDocument object using HTML5 parser if the content is HTML5 and the library is available.
* Use libxml parser otherwise.
*/
private function parseHtmlString(string
$content, string
$charset): \DOMDocument
{ if ($this->
canParseHtml5String($content)) { return $this->
parseHtml5($content,
$charset);
} return $this->
parseXhtml($content,
$charset);
} private function canParseHtml5String(string
$content): bool
{ if (!
$this->html5Parser
) { return false;
} if (false
=== ($pos =
stripos($content, '<!doctype html>'
))) { return false;
}