engelsystem/includes/pages/user_atom.php

<?php

// publically available page to feed the news to feedreaders
function user_atom() {
  global $ical_shifts, $user, $DISPLAY_NEWS;

  if (isset ($_REQUEST['key']) && preg_match("/^[0-9a-f]{32}$/", $_REQUEST['key']))
    $key = $_REQUEST['key'];
  else
    die("Missing key.");

  $user = User_by_api_key($key);
  if($user === false)
    die("Unable to find user.");
  if($user == null)
    die("Key invalid.");
  if(!in_array('atom', privileges_for_user($user['UID'])))
    die("No privilege for atom.");

  $news = sql_select("SELECT * FROM `News` " . (empty($_REQUEST['meetings'])? '' : 'WHERE `Treffen` = 1 ') . "ORDER BY `ID` DESC LIMIT " . sql_escape($DISPLAY_NEWS));

  header('Content-Type: application/atom+xml; charset=utf-8');
  $html = '<?xml version="1.0" encoding="utf-8"?>
  <feed xmlns="http://www.w3.org/2005/Atom">
  <title>Engelsystem</title>
  <id>' . $_SERVER['HTTP_HOST'] . htmlspecialchars(preg_replace('#[&?]key=[a-f0-9]{32}#', '', $_SERVER['REQUEST_URI'])) . '</id>
  <updated>' . date('Y-m-d\TH:i:sP', $news[0]['Datum']) . "</updated>\n";
  foreach ($news as $news_entry) {
    $html .= "  <entry>
    <title>" . htmlspecialchars($news_entry['Betreff']) . "</title>
    <link href=\"" . page_link_to_absolute("news_comments&amp;nid=") . "${news_entry['ID']}\"/>
    <id>" . preg_replace('#^https?://#', '', page_link_to_absolute("news")) . "-${news_entry['ID']}</id>
    <updated>" . date('Y-m-d\TH:i:sP', $news_entry['Datum']) . "</updated>
    <summary type=\"html\">" . htmlspecialchars($news_entry['Text']) . "</summary>
    </entry>\n";
}
$html .= "</feed>";
header("Content-Length: " . strlen($html));
echo $html;
die();
}
?>