Question

I’m inserting HTML paragraphs (<p></p>) into a piece of text, like this:

$text = '<p>' . preg_replace("/(\n|\r|\r\n)+/i", "</p><p>", $text) . '</p>' ;

Which seems to work well, except I don’t want any paragraphs within <code></code> blocks since content within those blocks are pre-formatted (using a white-space:pre; style).

I’m not sure how best to handle this. I’ve tried to remove any such tags after the above line of code, but that’s causing me some trouble and I figure it would be much better not to insert them in the first place.

Is it possible and/or practical to make the exclusion in the regex above? If not, what else?

Thanks

Edit: Came up with this code based on Nameless’ answer below. It appears to work.

$chunks = preg_split("/(<code>.*?<\/code>)/is", $text, -1, PREG_SPLIT_DELIM_CAPTURE) ;
$text = '' ;
foreach($chunks as $chunk) {
    if (preg_match("/^<code>/i", $chunk)) {
        $text .= $chunk ;
    } else {
        $text .= '<p>' . preg_replace("/(\n|\r)+/i", "</p><p>", $chunk) . '</p>' ;
    }
}

Answer 1

Well, it is possible with PCRE regex engine. Yet, highly irrational and resourse-heavy.

$text = '<p>' . preg_replace("/(\n|\r|\r\n)+(?!(.(?!<code>))*<\/code>)|(\n|\r|\r\n)+(?=<code>)/is", "</p><p>", $text) . '</p>' ;

Using DOM is probably the best solution, if you can spend some additional RAM on this operation.
If not, you could split your string beforehand in chunks of <code> … </code> and everything else, than use your regex on chunks not in <code>, than glue it back into string.