Question

I want to write symple (consisting of one preg_replace call) forum parser and I run into problems with nested tags.

E.g. if someone is quoting someone quoting someone, I cannot achieve correct behaviour.

When having:

[quote=Tom]

[quote=Jerry]
Lorem
[/quote]

Ipsum

[/quote]

Dolor.

I want something like this:

<blockquote>
    <p><strong>Tom wrote</strong></p>
    <blockquote>
       <p><strong>Jerry wrote:</strong></p>
      <p>Lorem</p>
    </blockquote>

    Ipsum
</blockquote>

Dolor.

I have this code:

preg_replace('~\[quote (.+)\](.+)\[/quote\]~is', '<blockquote><p><strong>$1</strong> wrote:</p><p>$2</p></blockquote>', $value);

This version is greedy. If I have two separate [quote] blocks, the regex wraps all the text between the first [quote] and the second [/quote].

If I add the U modifier, it’s too ungreedy – the first [quote] tag is paired with the first (nested and irrelevant) [/quote] tag.

Thanks for any help!

Answer 1

There is the PEAR HTML_BBCodeParser Package and also PHP has a native extension for parsing code like this, check this example: http://www.php.net/manual/en/function.bbcode-create.php