Convert to HTML Entities Between Code Tags
September 12, 2009 | Posted in Code Snippets, HTML, PHPIf 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?
I'm using something similar for the comments on this blog. After I read Matthew James Taylor's post about this, I tried to come up with something using a little less code.
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.
Buddy - you've just saved me hours of time!
Many thanks!
asdasdasd
Buddy - you've just saved me hours of time!
Many thanks!