Question

I’m trying to parse BBCode in my script. Now, it works seamelessly, until I try to indent BBCode that’s more than just bold or underline – such as spoiler, url, font size, etc. – then it screws up. Here’s my code:

function parse_bbcode($text) {
    global $db;
    $oldtext = $text;
    $bbcodes = $db->select('*', 'bbcodes');
    foreach ($bbcodes as $bbcode) {
        switch ($bbcode->type) {
            case 'simple': {
                $find = '{content}';
                $replace = '${1}';
                $text = preg_replace(
                    '/\['.$bbcode->tag.'\](.+)\[\/'.$bbcode->tag.'\]/i',
                    str_replace($find, $replace, $bbcode->html),
                    $text);
                    break;
            }
            case 'property':
            case 'options': {
                $find = array ( '{property}', '{content}' );
                $replace = array ( '${1}', '${2}' );
                $text = preg_replace(
                    '/\['.$bbcode->tag.'\=(.[^\"]*)\](.+)\[\/'.$bbcode->tag.'\]/i',
                    str_replace($find, $replace, $bbcode->html),
                    $text);
                    break;
            }
        }
    }
    return $text;
}

Now my guess is that the RegEx doesn’t like the recursiveness in the pattern. How can I improve it? A sample $bbcode object is as such:

stdClass::__set_state(array(
   'id' => '2',
   'name' => 'Italic',
   'type' => 'simple',
   'tag' => 'i',
   'button_image' => NULL,
   'button_text' => '<i>I</i>',
   'options' => '',
   'prompt' => NULL,
   'html' => '<i>{content}</i>',
   'order' => '1',
))
stdClass::__set_state(array(
   'id' => '3',
   'name' => 'URL',
   'type' => 'property',
   'tag' => 'url',
   'button_image' => NULL,
   'button_text' => 'http://',
   'options' => '',
   'prompt' => 'URL address',
   'html' => '<a href="{property}">{content}</a>',
   'order' => '4',
))

Answer 1

As gordon said in comments PHP has a BBCode parser, so no reason to reinvent the wheel.

The native parser is a PECL package though, so you will have to install it. If that’s not an option (for instance due to shared hosting), there is also a PEAR package: http://pear.php.net/package/HTML_BBCodeParser

In addition to those, you can take a look at forums using BB code source code, and either use their parser, or improve it. There is also several PHP implementations listed at http://www.bbcode.org/implementations.php