HtmlDocument::detectEncoding

public function detectEncoding()
{
	$result = '';
	if (empty($this->metaElements))
	{
		$this->metaElements = $this->extractElementAttributes('meta');
	}

	foreach($this->metaElements as $metaElement)
	{
		if (isset($metaElement['http-equiv']) && mb_strtolower($metaElement['http-equiv']) == 'content-type')
		{
			if (preg_match('/charset=([w-]+)/', $metaElement['content'], $matches))
			{
				$result = $matches[1];
				break;
			}
		}
		elseif (isset($metaElement['charset']))
		{
			$result = $metaElement['charset'];
			break;
		}
	}

	return $result;
}