HTMLPurifier iframe Vimeo and Youtube video

Question

How can I use HTMLPurifier to filter xss but also to allow iframe Vimeo and Youtube video?

require_once 'htmlpurifier/library/HTMLPurifier.auto.php';
$config = HTMLPurifier_Config::createDefault();
$config->set('HTML.Trusted', true);

$config->set('Filter.YouTube', true);
$config->set('HTML.DefinitionID', '1');
$config->set('HTML.SafeObject', 'true');
$config->set('Output.FlashCompat', 'true');

$config->set('HTML.FlashAllowFullScreen', 'true');

$purifier = new HTMLPurifier($config);
$temp = $purifier->purify($temp);

Answer 1

Using drupal 7.19 and the htmlpurifier module you can configure the following setting without needing to write this code.

See http://drupal.org/node/711728#comment-5600344

Answer 2

Also do not forget to set

URI.DisableExternalResources: false

if you've set it to true before.

Answer 3

I just read this blog entry, and successfully created and used the custom filter. I made some changes to the code and added Vimeo support:

/**
 * Based on: http://sachachua.com/blog/2011/08/drupal-html-purifier-embedding-iframes-youtube/
 * Iframe filter that does some primitive whitelisting in a somewhat recognizable and tweakable way
 */
class HTMLPurifier_Filter_MyIframe extends HTMLPurifier_Filter
{
    public $name = 'MyIframe';

    /**
     *
     * @param string $html
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return string
     */
    public function preFilter($html, HTMLPurifier_Config $config, HTMLPurifier_Context $context)
    {
        $html = preg_replace('#<iframe#i', '<img class="MyIframe"', $html);
        $html = preg_replace('#</iframe>#i', '</img>', $html);
        return $html;
    }

    /**
     *
     * @param string $html
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return string
     */
    public function postFilter($html, HTMLPurifier_Config $config, HTMLPurifier_Context $context)
    {
        $post_regex = '#<img class="MyIframe"([^>]+?)>#';
        return preg_replace_callback($post_regex, array($this, 'postFilterCallback'), $html);
    }

    /**
     *
     * @param array $matches
     * @return string
     */
    protected function postFilterCallback($matches)
    {
        // Domain Whitelist
        $youTubeMatch = preg_match('#src="https?://www.youtube(-nocookie)?.com/#i', $matches[1]);
        $vimeoMatch = preg_match('#src="http://player.vimeo.com/#i', $matches[1]);
        if ($youTubeMatch || $vimeoMatch) {
            $extra = ' frameborder="0"';
            if ($youTubeMatch) {
                $extra .= ' allowfullscreen';
            } elseif ($vimeoMatch) {
                $extra .= ' webkitAllowFullScreen mozallowfullscreen allowFullScreen';
            }
            return '<iframe ' . $matches[1] . $extra . '></iframe>';
        } else {
            return '';
        }
    }
}

Adding the filter to your HTML Purifier config

$config->set('Filter.Custom', array(new HTMLPurifier_Filter_MyIframe()));

Answer 4

For anyone who is struggling (how to enable iframe and allowfullscreen)

    $config = \HTMLPurifier_Config::createDefault();
    $config->set('HTML.SafeIframe', true);
    $config->set('URI.SafeIframeRegexp', '%^(https?:)?//(www\.youtube(?:-nocookie)?\.com/embed/|player\.vimeo\.com/video/)%'); //allow YouTube and Vimeo
    // This line is important allow iframe in allowed elements or it will not work    
    $config->set('HTML.AllowedElements', array('iframe'));// <-- IMPORTANT
    $config->set('HTML.AllowedAttributes','iframe@src,iframe@allowfullscreen');

    $def = $config->getHTMLDefinition(true);
    $def->addAttribute('iframe', 'allowfullscreen', 'Bool');

    $purifier = new \HTMLPurifier($config);
    $purifiedHtml = $purifier->purify($html);

Answer 5

Get rid of the %HTML.Trusted, %Filter.YouTube and %HTML.DefinitionID. They're probably interacting poorly with SafeObject/FlashCompat.

Answer 6

This much should do the trick

$text = "<iframe width='560' height='315' src='//www.youtube.com/embed/RGLI7QBUitE?autoplay=1' frameborder='0' allowfullscreen></iframe>";

require_once 'htmlpurifier/library/HTMLPurifier.auto.php';
$config = HTMLPurifier_Config::createDefault();
$config->set('HTML.Trusted', true);
$config->set('Filter.YouTube', true);

echo $purifier->purify($text);