Close open HTML tags in a string

Question

Situation is a string that results in something like this:

This is some text and here is a bold text then the post stop here....
         


        

Answer 1

And what about using PHP's native DOMDocument class? It inherently parses HTML and corrects syntax errors... E.g.:

$fragment = "
Title
Unclosed";
$doc = new DOMDocument();
$doc->loadHTML($fragment);
$correctFragment = $doc->getElementsByTagName('body')->item(0)->C14N();
echo $correctFragment;

However, there are several disadvantages of this approach. Firstly, it wraps the original fragment within the tag. You can get rid of it easily by something like (preg_)replace() or by substituting the ...->C14N() function by some custom innerHTML() function, as suggested for example at http://php.net/manual/en/book.dom.php#89718. The second pitfall is that PHP throws an 'invalid tag in Entity' warning if HTML5 or custom tags are used (nevertheless, it will still proceed correctly).