If you're ever posting a piece of code on your blog or whatever, you've probably realized that it's a pain to have to convert any special character to its HTML entity. Why not take the pain away and let PHP handle that for you?
There really isn't a foolproof method to pull this off, and I have been told that traversing the code using the DOM would be better, but this function (as ugly as it is) actually works quite well if you have a proper HTML structure with valid code.
It checks for any <code> and <pre> tags and converts any special characters inside them to there respective HTML entity. It even accounts for nested <code> and <pre> tags, as well as any attributes you give them.
The Function
function fixcodeblocks($string)
{
return preg_replace_callback('#<(code|pre)([^>]*)>(((?!</?\1).)*|(?R))*</\1>#si', 'specialchars', $string);
}
function specialchars($matches)
{
return '<'.$matches[1].$matches[2].'>'.htmlspecialchars(substr(str_replace('<'.$matches[1].$matches[2].'>', '', $matches[0]), 0, -(strlen($matches[1]) + 3))).'</'.$matches[1].'>';
}
echo fixcodeblocks($html);
That would turn something like this:
<h1>Heading</h1>
<p>Some stuff here, but no actually code yet.</p>
<p>Here is our first code that needs to be escaped: <code><div id="test">Something inside a DIV</div></code></p>
<pre id="test">
<html>
<head>
<meta name="author" content="First Last" />
</head>
<body>
<p>Hey</p>
</body>
<div id="nested">
<div id="nest-inside">
<p>Inside nest</p>
</div>
</div>
<code>Another code block inside some code.</code>
</html>
</pre>
<h2>More Content</h2>
into this:
<h1>Heading</h1>
<p>Some stuff here, but no actually code yet.</p>
<p>Here is our first code that needs to be escaped: <code><div id="test">Something inside a DIV</div></code></p>
<pre id="test">
<html>
<head>
<meta name="author" content="First Last" />
</head>
<body>
<p>Hey</p>
</body>
<div id="nested">
<div id="nest-inside">
<p>Inside nest</p>
</div>
</div>
<code>Another code block inside some code.</code>
</html>
</pre>
<h2>More Content</h2>
Feel free to offer any suggestions or improvements you might have, as well as any other ways of accomplishing this.
Janeth Kent
Licenciada en Bellas Artes y programadora por pasión. Cuando tengo un rato retoco fotos, edito vídeos y diseño cosas. El resto del tiempo escribo en MA-NO WEB DESIGN END DEVELOPMENT.