Valid RSS 2.0 Generator Class

I've been searching Google and couldn't find anything except documentation. So I'm posting this here in hopes that it will help someone else from having to go through a few hours of Trial and Error getting their feed to validate. This is tested only to pass the W3.org RSS 2.0 Validator.

I initially programmed it with required key values and things utilizing our custom api, but removed all of that for a stripped down basic version. If anyone has any updates/improvements to this feed or has any classes for other kinds of feeds I'd definitely be interested in hearing about them.

Post a comment if you use this and find it useful.

<?php
class FeedRss {
 
 var $feed = "";
 
 /*===========================================*/
 /* Public Functions
 /*===========================================*/
 public function create ($paramList) {
     $paramList = $this->cleanParamList($paramList);    
 
     $this->feed .= "<?xml version='1.0' encoding='iso-8859-1'?>\n";
     $this->feed .= "    <rss version='2.0' xmlns:atom='http://www.w3.org/2005/Atom'>\n";
     $this->feed .= "        <channel>\n";
     $this->feed .= "            <atom:link href='".$paramList['location']."' rel='self' type='application/rss+xml' />\n";
     $this->feed .= "            <title>".$paramList['title']."</title>\n";
  
  if (array_key_exists("copyright", $paramList)) {
       $this->feed .= "            <copyright>".$paramList['copyright']."</copyright>\n";
  }
  
  $this->feed .= "            <link>".$paramList['link']."</link>\n";
  $this->feed .= "            <description>".$paramList['description']."</description>\n";
  
  if (is_numeric($paramList["updated"])) {
   $this->feed .= "            <lastbuilddate>".date('D, d M Y H:i:s O', $paramList['updated'])."</lastBuildDate>\n";
  } else {
   $this->feed .= "            <lastbuilddate>".$paramList['updated']."</lastBuildDate>\n";
  }
  
  $this->feed .= "            <language>".$paramList['language']."</language>\n";
  
  if (array_key_exists("image", $paramList)) {
   $imageInput = array_merge($paramList["image"], array(
    "title" => $paramList["title"]
   ));
   $this->addImage($imageInput);
  }
 }
 
 public function addItem ($paramList) {
  $paramList = $this->cleanParamList($paramList);    
 
  $this->feed .= "        <item>\n";
  $this->feed .= "            <title><![CDATA[".$paramList['title']."]]></title>\n";
  $this->feed .= "            <link>".$paramList['link']."</link>\n";
  $this->feed .= "            <description><![CDATA[".$paramList['description']."]]></description>\n";
  
  if (array_key_exists("author", $paramList)) {
   $this->feed .= "            <author>".$paramList['author']."</author>\n";
  }
  
  if (array_key_exists("guid", $paramList)) {
   $this->feed .= "            <guid>".$paramList['guid']."</guid>\n";
  }
  
  if (is_numeric($paramList["updated"])) {
   $this->feed .= "            <pubdate>".date('D, d M Y H:i:s O', $paramList['updated'])."</pubDate>\n";
  } else {
   $this->feed .= "            <pubdate>".$paramList['updated']."</pubDate>\n";
  }
  
  if (array_key_exists("category", $paramList)) {
   $this->feed .= "            <category>".$paramList['category']."</category>\n";
  }
  
  $this->feed .= "        </item>\n";
 }
 
 public function get () {
  $this->feed .= "        </channel>\n";
  $this->feed .= "    </rss>";
  
  return $this->feed;
 }
 
 /*===========================================*/
 /* Private Functions
 /*===========================================*/
 
 private function addImage ($paramList) {
  $this->feed .= "            <image>\n";
  $this->feed .= "                <url>".$paramList["url"]."</url>\n";
  $this->feed .= "                <width>".$paramList["width"]."</width>\n";
  $this->feed .= "                <height>".$paramList["height"]."</height>\n";
  $this->feed .= "                <title>".$paramList["title"]."</title>\n";
  $this->feed .= "                <link>".$paramList["link"]."</link>\n";
  $this->feed .= "            </image>\n";
 }    
 private function cleanParamList ($paramList) {
  $ignoreParam = array("updated", "description");
  
  $replaceList = array(
   "&" => "&amp;",
   "–" => "&ndash;",
   "—" => "&mdash;",
   "¡" => "&iexcl;",
   "¿" => "&iquest;",
   "«" => "&raquo;",
   "<" => "&lt;",
   ">" => "&gt;",
   "$" => "&#36;",
   "»" => "&laquo;",
   "¢" => "&cent;",
   "©" => "&copy;",
   "÷" => "&divide;",
   "µ" => "&micro;",
   "·" => "&middot;",
   "¶" => "&para;",
   "±" => "&plusmn;",
   "€" => "&euro;",
   "£" => "&pound;",
   "®" => "&reg;",
   "§" => "&sect;",
   "¥" => "&yen;",
   "’" => "'",
   "“" => "\"",
   "”" => "\""
  );
  
  foreach ($paramList as $key => $value) {
   if (!in_array($key, $ignoreParam)) {
    $paramList[$key] = str_replace(array_keys($replaceList), array_values($replaceList), $str);
   }
  }
  
  return $paramList;
 }
}
?>

Usage:

//if writing to a file via cron or any other method, comment out this header
header("Content-Type: application/xml; charset=ISO-8859-1");

$feed->create(array(
 "title" => "Domain.com News",
 "copyright" => "Copyright (c) ".date("Y")." Site Inc. All rights reserved.",
 "link" => "http://www.domain.com",
 "location" => "http://feed.domain.com/feed.xml",
 "description" => "All of the latest news",
 "language" => "en-us",
 "image" => array(
 "url" => "http://www.domain.com/image/branding/rss-logo.jpg",
 "height" => 50,
 "width" => 50,
 "title" => "RSS feed from Domain.com",
 "link" => "http://www.domain.com"
)
));

//add as many items as you'd like
$feed->addItem(array(
 "title" => $news["title"],
 "link" => "http://www.domain.com/index.php?sec=news&act=view&id=".$news["id"],
 "guid" => "http://www.domain.com/index.php?sec=news&act=view&id=".$news["id"],
 "description" => $tempNewsItem["preview_cache"],
 "author" => "news@domain.com (author)", //for proper validation you should have an email AND an author's name of some sort
 "category" => "Computer Hardware",
 "updated" => $news["posted"]
));

//this can also be used to write to a file
echo $feed->get();