Is it possible to make HTML Purifier to replace double with and at the same time not to delete single one?

Question

Is it possible to make HTML Purifier to replace double <br> with <p> and at the same time not to delete single one? How easy it is to make?

We are trying to change double <br> into <p> in user genereated content and we use HTML Purifier for this purpose. But it seems this library cuts out all single <br> at the same time.

p.s. I am not a programmer, I am a product manager. And I asked to configure the text parser (we use HTML Purifier) on our service to let it use tags <p> insted of <br><br> in user generated texts. The programmer has done this but the next problem arises: the parser begins to cut out single line break <br>. And I was told that it is impossible or very hard to fix it. I am confused, I worked with regular expressions before and this was not a problem at all.

Answer 1

It can be done pretty easy. The first (and definitely most easy method) is just to replace <br><br> with </p><p> and wrap the whole content in <p></p> tags.

$string = str_replace( '<br><br>', '</p><p>', $string );
$string = str_replace( '<br /><br />', '</p><p>', $string );
$string = str_replace( '<br><br />', '</p><p>', $string );
$string = str_replace( '<br /><br>', '</p><p>', $string );
echo "<p>$string</p>";

But a more cleaner solution is this. Use regex to identify the tags and then do a replace. It searches for <br>,<br >,<br />, etc. and then does a replace. Like so:

function replace_br($data) {
    $data = preg_replace('#(?:<br\s*/?>\s*?){2,}#', '</p><p>', $data);
    return "<p>$data</p>";
}

Info found here: php: replacing double <br /> with </p><p>