XHTML Filter

[GameMusic]

I'm trying to make a filter that, among other things, turns unclosed XHTML tags into their htmlspecialchars() equivalents.

I made a recursive function to try to handle this. The board will probably mangle this regexp, but I'll try to post it anyway.

function DualTags($string) {
	// call htmlspeacilchars($string) before calling this

// turn good tags back to normal
return preg_replace(
'/<(\\\\w+?)((?:\\\\s+\\\\w+=".*?")*?)>(.*?)<\\\\/\\\\1>/ise',
"'<\\$1' . str_replace('\\\\\\"', '\\"', '\\$2') . '>'
. DualTags(str_replace('\\\\\\"', '\\"', '\\$3')) . '</\\$1>'",
$string);
}

It works fine, but nested tags of the same type don't work. I can have

<b><i></i></b>

or

<table> </table> <table> </table>

but

<table> <table> </table> </table>

turns into

<table> &lt;table&gt; </table> &lt;/table&gt;

Any ideas? I have a similar problem when trying to support custom markup like [font][font][/font][/font].

[drawmack]

use css positioning instead of nested tables

http://www.w3schools.com/css

[GameMusic]

This is for user-submitted input and styles may be disabled. It's a security filter. I know that just disallowing nested tags would be easier, but I want to allow as much customization as possible.

[drawmack]

disabling styles is a bad idea, especially if you expect them to use xhtml which took away the font command.

[GameMusic]

I don't want to be a pain, but this is kind of moot, because I can't nest divs, or spans, or anything else.