Question

How can I strip off certain html tags and allow some of them?

For instance,

I want to strip off span tags but allow the span with underline.

<span style="text-decoration: underline;">Text</span>

I want to allow p but I want to remove any styles or classes inside the p for instance,

<p class="99light">Text</p> the class inside the p tag should be removed – I just want a clean p tag.

The is the line I have so far,

strip_tags($content, '<p><a><br><em><strong><ul><li>');

Answer 1

You can’t. You’ll need to use an XML/HTML parser to do that:

// with DOMDocument it might look something like this.
$dom = new DOMDocument();
$dom->loadHTML( $content );
foreach( $dom->getElementsByTagName( "p" ) as $p )
{
    // removes all attributes from a p tag.
    /*
    foreach( $p->attributes as $attrib )
    {
        $p->removeAttributeNode( $attrib );
    }
    */
    // remove only the style attribute.
    $p->removeAttributeNode( $p->getAttributeNode( "style" ) );
}
echo $dom->saveHTML();