Question

I have a <textarea> where I am allowing user content to be submitted. I would like to allow a couple tags such as <b>, <i>,<blockquote>, and <del>. However, since the content will be displayed in the page, I have to ensure that there are no unclosed tags.

I know I can use strip_tags($textarea, '<b><i><blockquote><del>'), but how can I then ensure that all the remaining tags are properly closed?

Answer 1

You could use Tidy. It will clean and sanitize your HTML.

This comment, on php.net, address your problem and shows how to solve it: http://www.php.net/manual/en/tidy.examples.basic.php#89334

Cleaning an html fragment (OO support
seems to half-arsed for now)

This will ensure all tags are closed,
without adding any html/head/body tags
around it.

<?php
$tidy_config = array( 
  'clean' => true, 
  'output-xhtml' => true, 
  'show-body-only' => true, 
  'wrap' => 0, 
); 

$tidy = tidy_parse_string($html_fragment, $tidy_config, 'UTF8'); 
$tidy->cleanRepair(); 
echo $tidy; 
?>