插件50：把HTML转换为适用于移动浏览器的HTML页面

<?php // Plug-in 50: HTML To Mobile

// This is an executable example with additional code supplied
// To obtain just the plug-ins please click on the Download link

$url    = "http://yahoo.com";
$html   = file_get_contents($url);
$style  = "no";
$images = "yes";

echo    PIPHP_HTMLToMobile($html, $url, $style, $images);

function PIPHP_HTMLToMobile($html, $url, $style, $images)
{
   // Plug-in 50: HTML To Mobile
   //
   // This plug-in takes a string containing a complete HTML
   // page and turns it into a format more quickly and clearly
   // displayed by a mobile browser. The arguments required are:
   //
   //    $html:   HTML to convert to Mobile Browser
   //    $url:    URL of page being converted
   //    $style:  If "yes" keep style & JavaScript
   //    $images: If "yes" keep images

   $dom   = new domdocument();
   @$dom  ->loadhtml($html);
   $xpath = new domxpath($dom);
   $hrefs = $xpath->evaluate("/html/body//a");
   $links = array();
   $to    = array();
   $count = 0;
   $html  = str_replace('&', '&',         $html);
   $html  = str_replace('&',     '!!**1**!!', $html);

   for ($j = 0 ; $j < $hrefs->length ; ++$j)
      $links[] = $hrefs->item($j)->getAttribute('href');

   $links = array_unique($links);
   sort($links);

   foreach ($links as $link)
   {
      if ($link != "")
      {
         $temp = str_replace('!!**1**!!', '&', $link);
         $to[$count] = urlencode(PIPHP_RelToAbsURL($url, $temp));
         $html = str_replace("href=\"$link\"",
            "href=\"!!$count!!\"", $html);
         $html = str_replace("href='$link'",
            "href='!!$count!!'",   $html);
         $html = str_replace("href=$link",
            "href=!!$count!!",     $html);
         ++$count;
      }
   }

   for ($j = 0 ; $j < $count ; ++$j)
      $html = str_replace("!!$j!!", $to[$j], $html);

   $html = str_replace('http%3A%2F%2F', 'http://', $html);
   $html = str_replace('!!**1**!!', '&', $html);

   if (strtolower($style) != "yes")
   {
      $html = preg_replace('/[\s]+/', ' ', $html);
      $html = preg_replace('/<script[^>]*>.*?<\/script>/i', '',
         $html);
      $html = preg_replace('/<style[^>]*>.*?<\/style>/i', '',
         $html);
   }

   $allowed = "<a><p><h><i><b><u><s>";
   if (strtolower($images) == "yes") $allowed .= "<img>";
   return strip_tags($html, $allowed);
}

// The below function is repeated here to ensure that it's
// available to the main function which relies on it

function PIPHP_RelToAbsURL($page, $url)
{
   // Plug-in 21: Relative To Absolute URL
   //
   // This plug-in accepts the absolute URL of a web page
   // and a link featured within that page. The link is then
   // turned into an absolute URL which can be independently
   // accessed. Only applies to http:// URLs. Arguments are:
   //
   //    $page: The web page containing the URL
   //    $url:  The URL to convert to absolute

   if (substr($page, 0, 7) != "http://") return $url;
   
   $parse = parse_url($page);
   $root  = $parse['scheme'] . "://" . $parse['host'];
   $p     = strrpos(substr($page, 7), '/');
   
   if ($p) $base = substr($page, 0, $p + 8);
   else $base = "$page/";
   
   if (substr($url, 0, 1) == '/')           $url = $root . $url;
   elseif (substr($url, 0, 7) != "http://") $url = $base . $url;

   return $url;
}

?>

插件说明：

插件接受一个包含需要转换的HTML页面的字符串和其他参数，返回一个删除需多格式控制元素后、使用正常格式的HTML文档。

$html 需要转换的HTML页面。

$url 需要转换的页面的URL地址

$style 如果值为yes，则保留样式和javascript元素，否则删除。

$images 如果值为yes，保留图像，否则删除。