Remove all attributes from html tags

Question

I have this html code:

<p style="padding:0px;">   <strong style="padding:0;margin:0;">hello</strong> </p> 

How can I remove attributes from all tags? I'd like it to look like this:

<p>   <strong>hello</strong> </p> 

Answer 1

Adapted from my answer on a similar question

$text = '<p style="padding:0px;"><strong style="padding:0;margin:0;">hello</strong></p>';  echo preg_replace("/<([a-z][a-z0-9]*)[^>]*?(\/?)>/si",'<$1$2>', $text);  // <p><strong>hello</strong></p> 

The RegExp broken down:

/              # Start Pattern  <             # Match '<' at beginning of tags  (             # Start Capture Group $1 - Tag Name   [a-z]        # Match 'a' through 'z'   [a-z0-9]*    # Match 'a' through 'z' or '0' through '9' zero or more times  )             # End Capture Group  [^>]*?        # Match anything other than '>', Zero or More times, not-greedy (wont eat the /)  (\/?)         # Capture Group $2 - '/' if it is there  >             # Match '>' /is            # End Pattern - Case Insensitive & Multi-line ability 

Add some quoting, and use the replacement text <$1$2> it should strip any text after the tagname until the end of tag /> or just >.

Please Note This isn't necessarily going to work on ALL input, as the Anti-HTML + RegExp will tell you. There are a few fallbacks, most notably <p style=">"> would end up <p>"> and a few other broken issues... I would recommend looking at Zend_Filter_StripTags as a more full proof tags/attributes filter in PHP

Answer 2

Here is how to do it with native DOM:

$dom = new DOMDocument;                 // init new DOMDocument $dom->loadHTML($html);                  // load HTML into it $xpath = new DOMXPath($dom);            // create a new XPath $nodes = $xpath->query('//*[@style]');  // Find elements with a style attribute foreach ($nodes as $node) {              // Iterate over found elements     $node->removeAttribute('style');    // Remove style attribute } echo $dom->saveHTML();                  // output cleaned HTML 

If you want to remove all possible attributes from all possible tags, do

$dom = new DOMDocument; $dom->loadHTML($html); $xpath = new DOMXPath($dom); $nodes = $xpath->query('//@*'); foreach ($nodes as $node) {     $node->parentNode->removeAttribute($node->nodeName); } echo $dom->saveHTML();