[SOLVED] convert part of a string using preg_replace

[nuttycoder]

Hi Guys,

 

I'm trying to print some code snippets to the screen that's mixed with normal html what I'm trying to do is use htmlentities to convert the snippets. This would only convert text inside [ code ] [ /code ] tags.

 

Using preg_replace I've managed to isolate the snippets but I cannot use htmlentities without causing an error.

 

As I need to add the snippets back into the string it came from before bring printed.

 

Here's what I've been using replacing all code tags with <pre class="codeprint">snippets here</pre>

 

$pr->postDesc = preg_replace("/\[code\](.+?)\[\/code\]/is","<pre class=\"codeprint\">$1</pre>", $pr->postDesc);

 

An example of what $pr->postDesc contains:

 

<p>testing</p>

 

[ code ]

<?php echo $test;?>

[ /code ]

 

Hope you can understand what I mean.

[Alex]

You're gonna want to use preg_replace_callback(). Something like this should work:

 

$pr->postDesc = preg_replace_callback("/\[code\](.+?)\[\/code\]/is", create_function('$matches', "return '<pre class=\"codeprint\">' . htmlentities($matches[1]) . '</pre>';", $pr->postDesc);

[thebadbad]

Alex kinda beat me to it, though his code has an error (using double quotes for the second parameter in create_function()).

 

You're best off using preg_replace_callback(), since using preg_replace() with the e modifier (as I guess you may have tried) gives us some escaping issues (article). Code:

 

<?php
$pr->postDesc = preg_replace_callback(
'~\[code\](.*?)\[/code\]~is',
create_function(
	'$matches',
	'return \'<pre class="codeprint">\' . htmlentities($matches[1], ENT_QUOTES) . \'</pre>\';'
),
$pr->postDesc
);
?>

 

I'm assuming you're using square brackets for your code tags, since that's what you did in the pattern you said you've been using.

 

If you want to syntax highlight the snippets, use highlight_string() instead of htmlentities().

[nuttycoder]

Thanks Guys I should have consulted the manual to see if there way a better way preg_replace_callback is the obvious choice now it's been pointed out to me

 

Works a treat.

 

I'm not using highlight_string as my code snippets are not limited to just php so I'm using google's prettify syntax highlight plugin.

 

Thanks again guys much appreciated!!