<?php
/**
 * @package AMP - Accelerated Mobile Pages
 * @since 0.1
 */
function etruel_amp_strip_tags_content($text, $tags = '', $invert = FALSE) { 

	  preg_match_all('/<(.+?)[\s]*\/?[\s]*>/si', trim($tags), $tags); 
	  $tags = array_unique($tags[1]); 
	    
	  if(is_array($tags) AND count($tags) > 0) { 
	    if($invert == FALSE) { 
	      return preg_replace('@<(?!(?:'. implode('|', $tags) .')\b)(\w+)\b.*?>.*?</\1>@si', '', $text); 
	    } 
	    else { 
	      return preg_replace('@<('. implode('|', $tags) .')\b.*?>.*?</\1>@si', '', $text); 
	    } 
	  } 
	  elseif($invert == FALSE) { 
	    return preg_replace('@<(\w+)\b.*?>.*?</\1>@si', '', $text); 
	  } 
	return $text; 
}
?>