/textpattern/publish/rss.php

<?php

/*
	This is Textpattern
	Copyright 2005 by Dean Allen - all rights reserved.

	Use of this software denotes acceptance of the Textpattern license agreement

$HeadURL$
$LastChangedRevision$

*/


// -------------------------------------------------------------
	function rss()
	{
		global $prefs,$thisarticle;
		set_error_handler('feedErrorHandler');
		ob_clean();
		extract($prefs);

		extract(doSlash(gpsa(array('limit','area'))));

		// build filter criteria from a comma-separated list of sections and categories
		$feed_filter_limit = get_pref('feed_filter_limit', 10);
		$section = gps('section');
		$section = ($section ? array_slice(array_unique(do_list($section)), 0, $feed_filter_limit) : array());
		$category = gps('category');
		$category = ($category ? array_slice(array_unique(do_list($category)), 0, $feed_filter_limit) : array());
		$st = array();
		foreach ($section as $s)
		{
			$st[] = fetch_section_title($s);
		}
		$ct = array();
		foreach ($category as $c)
		{
			$ct[] = fetch_category_title($c);
		}

		$sitename .= ($section) ? ' - '.join(' - ', $st) : '';
		$sitename .= ($category) ? ' - '.join(' - ', $ct) : '';
		$dn = explode('/',$siteurl);
		$mail_or_domain = ($use_mail_on_feeds_id)? eE($blog_mail_uid):$dn[0];

		// feed header
		$out[] = tag('http://textpattern.com/?v='.$version, 'generator');
		$out[] = tag(doSpecial($sitename),'title');
		$out[] = tag(hu,'link');
		$out[] = '<atom:link href="'.pagelinkurl(array('rss'=>1,'area'=>$area,'section'=>$section,'category'=>$category,'limit'=>$limit)).'" rel="self" type="application/rss+xml" />';
		$out[] = tag(doSpecial($site_slogan),'description');
		$last = fetch('unix_timestamp(val)','txp_prefs','name','lastmod');
		$out[] = tag(safe_strftime('rfc822',$last),'pubDate');
		$out[] = callback_event('rss_head');

		// feed items
		$articles = array();
		$section = doSlash($section);
		$category = doSlash($category);

		if (!$area or $area=='article') {

			$sfilter = (!empty($section)) ? "and Section in ('".join("','", $section)."')" : '';
			$cfilter = (!empty($category))? "and (Category1 in ('".join("','", $category)."') or Category2 in ('".join("','", $category)."'))" : '';
			$limit = ($limit) ? $limit : $rss_how_many;
			$limit = intval(min($limit,max(100,$rss_how_many)));

			$frs = safe_column("name", "txp_section", "in_rss != '1'");
			if ($frs) foreach($frs as $f) $query[] = "and Section != '".doSlash($f)."'";
			$query[] = $sfilter;
			$query[] = $cfilter;

			$expired = ($publish_expired_articles) ? '' : ' and (now() <= Expires or Expires = '.NULLDATETIME.') ';
			$rs = safe_rows_start(
				"*, unix_timestamp(Posted) as uPosted, unix_timestamp(LastMod) as uLastMod, unix_timestamp(Expires) as uExpires, ID as thisid",
				"textpattern",
				"Status = 4 ".join(' ',$query).
				"and Posted < now()".$expired."order by Posted desc limit $limit"
			);

			if($rs) {
				while ($a = nextRow($rs)) {
					extract($a);
					populateArticleData($a);

					$cb = callback_event('rss_entry');

					$a['posted'] = $uPosted;

					$permlink = permlinkurl($a);
					$summary = trim(replace_relative_urls(parse($thisarticle['excerpt']), $permlink));
					$content = trim(replace_relative_urls(parse($thisarticle['body']), $permlink));

					if ($syndicate_body_or_excerpt) {
						# short feed: use body as summary if there's no excerpt
						if (!trim($summary))
							$summary = $content;
						$content = '';
					}

					if ($show_comment_count_in_feed) {
						$count = ($comments_count > 0) ? ' ['.$comments_count.']' : '';
					} else $count = '';

					$Title = escape_title(strip_tags($Title)).$count;

					$thisauthor = get_author_name($AuthorID);

					$item = tag($Title,'title').n.
						(trim($summary) ? tag(n.escape_cdata($summary).n,'description').n : '').
						(trim($content) ? tag(n.escape_cdata($content).n,'content:encoded').n : '').
						tag($permlink,'link').n.
						tag(safe_strftime('rfc822',$a['posted']),'pubDate').n.
						tag(htmlspecialchars($thisauthor),'dc:creator').n.
						tag('tag:'.$mail_or_domain.','.$feed_time.':'.$blog_uid.'/'.$uid,'guid', ' isPermaLink="false"').n.
						$cb;



					$articles[$ID] = tag($item,'item');

					$etags[$ID] = strtoupper(dechex(crc32($articles[$ID])));
					$dates[$ID] = $uPosted;

				}

			}
		} elseif ($area=='link') {

			$cfilter = ($category) ? "category='$category'" : '1';
			$limit = ($limit) ? $limit : $rss_how_many;
			$limit = intval(min($limit,max(100,$rss_how_many)));

			$rs = safe_rows_start("*, unix_timestamp(date) as uDate", "txp_link", "$cfilter order by date desc limit $limit");

			if ($rs) {
				while ($a = nextRow($rs)) {
					extract($a);
					$item =
						tag(doSpecial($linkname),'title').n.
						tag(doSpecial($description),'description').n.
						tag(doSpecial($url),'link').n.
						tag(safe_strftime('rfc822',$uDate),'pubDate');
					$articles[$id] = tag($item,'item');

					$etags[$id] = strtoupper(dechex(crc32($articles[$id])));
					$dates[$id] = $date;
				}
			}
		}

		if (!$articles) {
			if ($section) {
				if (safe_field('name', 'txp_section', "name in ('".join("','", $section)."')") == false) {
					txp_die(gTxt('404_not_found'), '404');
				}
			} elseif ($category) {
				switch ($area) {
					case 'link':
							if (safe_field('id', 'txp_category', "name = '$category' and type = 'link'") == false) {
								txp_die(gTxt('404_not_found'), '404');
							}
					break;

					case 'article':
					default:
							if (safe_field('id', 'txp_category', "name in ('".join("','", $category)."') and type = 'article'") == false) {
								txp_die(gTxt('404_not_found'), '404');
							}
					break;
				}
			}
		} else {
			//turn on compression if we aren't using it already
			if (extension_loaded('zlib') && ini_get("zlib.output_compression") == 0 && ini_get('output_handler') != 'ob_gzhandler' && !headers_sent()) {
				// make sure notices/warnings/errors don't fudge up the feed
				// when compression is used
				$buf = '';
				while ($b = @ob_get_clean())
					$buf .= $b;
				@ob_start('ob_gzhandler');
				echo $buf;
			}

			handle_lastmod();
			$hims = serverset('HTTP_IF_MODIFIED_SINCE');
			$imsd = ($hims) ? strtotime($hims) : 0;

			if (is_callable('apache_request_headers')) {
				$headers = apache_request_headers();
				if (isset($headers["A-IM"])) {
					$canaim = strpos($headers["A-IM"], "feed");
				} else {
					$canaim = false;
				}
			} else {
				$canaim = false;
			}

			$hinm = stripslashes(serverset('HTTP_IF_NONE_MATCH'));

			$cutarticles = false;

			if ($canaim !== false) {
				foreach($articles as $id=>$thing) {
					if (strpos($hinm, $etags[$id]) !== false) {
						unset($articles[$id]);
						$cutarticles = true;
						$cut_etag = true;
					}

					if ($dates[$id] < $imsd) {
						unset($articles[$id]);
						$cutarticles = true;
						$cut_time = true;
					}
				}
			}

			if (isset($cut_etag) && isset($cut_time)) {
				header("Vary: If-None-Match, If-Modified-Since");
			} else if (isset($cut_etag)) {
				header("Vary: If-None-Match");
			} else if (isset($cut_time)) {
				header("Vary: If-Modified-Since");
			}

			$etag = @join("-",$etags);

			if (strstr($hinm, $etag)) {
				txp_status_header('304 Not Modified');
				exit(0);
			}

			if ($cutarticles) {
				//header("HTTP/1.1 226 IM Used");
				//This should be used as opposed to 200, but Apache doesn't like it.
				//http://intertwingly.net/blog/2004/09/11/Vary-ETag/ says that the status code should be 200.
				header("Cache-Control: no-store, im");
				header("IM: feed");
			}
		}

		$out = array_merge($out, $articles);

		header("Content-Type: application/rss+xml; charset=utf-8");
		if (isset($etag)) header('ETag: "'.$etag.'"');
		return
			'<?xml version="1.0" encoding="utf-8"?>'.n.
			'<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom">'.n.
			tag(join(n,$out),'channel').n.
			'</rss>';
	}


// DEPRECATED FUNCTIONS
// included for backwards compatibility with older plugins only
	function rss_safe_hed($toUnicode) {

		if (version_compare(phpversion(), "5.0.0", ">=")) {
			$str =  html_entity_decode($toUnicode, ENT_QUOTES, "UTF-8");
		} else {
			$trans_tbl = get_html_translation_table(HTML_ENTITIES);
			foreach($trans_tbl as $k => $v) {
				$ttr[$v] = utf8_encode($k);
			}
			$str = strtr($toUnicode, $ttr);
		}
		return $str;
	}

?>