preg_replace - replace string with php-code

Hi.

I have a parser-function, which takes BBCode-ish [bracket]-code, and replaces these with the desired content. This works fine, as long as I replace the BBCode string with say HTML or something similar.

What I want, though, is for a certain replacement to contain a PHP if-function - and this I can't get to work. I was looking at the preg_replace manual, but couldn't really find anything regarding this.

Does anyone know if it's possible? Currently, I have something similar to this (this is stripped down to just the lines in question):

function parseDBText($value, $userrole_name) {
    // code replacements
    $value = preg_replace('#\[urlintern\=(.+)\](.+)\[\/urlintern\]#iUs', '<a href="index.php?page=$1">$2</a>', $value);
    $value = preg_replace('#\[role\=(.+)\](.+)\[\/role\]#iUs', "<?php if ($userrole_name == 'Superadmin') { echo $userrole_name; ?>$2<?php } ?>", $value);
        return($value);
}

PHP:

 

Just a quick update - the replacement code in the above example is the one that doesn't work - no errors or anything, it just doesn't work - it removes the [role]-bbcode, but does not trigger the if-statement - if I replace the php-code in the replacement with say, a <span class="role"> it replaces it perfectly. And the [role] is surrounding the [urlintern]-code, so it's meant as a way to hide certain internal urls from view for certain users.

 

In PHP you can not place control structures (if, switch, loop, etc..) as params. You would need to do the if statement beforehand and construct the $replacement as a string then pass it to preg_replace, ex:

<?php
if ($userrole_name == 'Superadmin') {
    $replacement = $userrole_name . '$2';
} else {
    $replacement = '$2';
}

$value = preg_replace('#\[role\=(.+)\](.+)\[\/role\]#iUs', $replacement, $value);

Code (markup):

 

Okay. I was afraid it was something like that. That means I'll have to rethink a few things when it comes to the BBCode, but elsewise it'll be fine. Thanks for the help!

 

You can execute functions or a single expression on preg_replace using the PREG_REPLACE_EVAL modifier (e), ex:

<?php
$value = '[role=test]test2 [/role]';
$value = preg_replace('#\[role\=(.+)\](.+)\[\/role\]#iUse', "trim('$2')", $value);
echo $value;

PHP:

Additionally, you can use your custom function using http://php.net/manual/en/function.preg-replace-callback.php method.

 

I ended up doing the following, within my function:

  $value = preg_replace_callback('#\[role\=(.+)\](.+)\[\/role\]#iUs', function ($matches) use ($userrole) { if ($matches[1] >= $userrole) { return $matches[2]; }; }, $value);
 

PHP: