Blog display code, keeping other content in post - php

Question

Alright, I have some code that will find a <code></code> tag set and clean up any code inside of it so it displays instead of functioning like regular code. Everything works, but my problem is how can I find the tag set/multiple tag sets inside, say, $content. Clean the code, and still have ALL of the other content in it? Here is my code, the problem is it checks for matches, and when it finds one it cleans it. But after it cleans it it has no way to put it back into it's original position $content. ($content is being grabbed from a form)
<?php
preg_match_all("'<code>(.*?)</code>'si", $html, $match);
if ($match) {
foreach ($match[1] as $snippet) {
$fixedCode = htmlspecialchars($snippet, ENT_QUOTES);
}
}
?>
What do I do with $fixedCode, now that it is clean?

Answer 1

Using regex for parsing HTML is bad. I'd suggest getting familiar with a DOM parser, such as PHP's DOM module.
The DOM extension allows you to operate on XML documents through the DOM API with PHP 5.
Using the DOM module, in order to get the HTML/data from <code> tags in the document, you'd want to do something like this:
<?php
//So many variables!
$html = "<div> Testing some <code>code</code></div><div>Nother div, nother <code>Code</code> tag</div>";
$dom_doc = new DOMDocument;
$dom_doc->loadHTML($html);
$code = $dom_doc->getElementsByTagName('code');
foreach ($code as $scrap) {
echo htmlspecialchars($scrap->nodeValue, ENT_QUOTES), "<br />";
}
?>