为 WordPress 增加 RSS Reader 功能
另外，MagpieRSS 只是 RSS 分析器，本身并不提供 RSS 发掘功能，在应用了该分析器的诸多开源程序中，注意到有 Gregarius， 一款很不错的 RSS 聚合程序。如果用过这套聚合程序，就知道在后台添加频道的时候，可以仅提供网址来自动发掘可用的 RSS 地址清单，所以利用这部分程序，我们在没有提供链接的 RSS 地址的情况下，也可以自动分析出 RSS 地址，然后调用 get_list_of_rss() 函数。MagpieRSS 中该部分代码在 util.php 中，主要是 getUrl() 和 extractFeeds() 两个函数。我将其放到 WordPress 下的 rss-functions.php 文件中使用。
getUrl() 和 extractFeeds()
PHP 代码:
/********************************************/
/********************************************/
/**
* Fetches a remote URL and returns the content
*/
function getUrl($url, $maxlen = 0) {
//Bug: in windows, scheme returned by parse_url contains the drive letter
//of the file so a test like !isset(scheme) does not work
//maybe it would be better to only use is_file() which only detect
//local files?
$urlParts = parse_url($url);
if (@is_file($url) || (!isset($urlParts['scheme']) && !isset($urlParts['host'])) ) {
//local file!
$c = "";
$h = @fopen($url, "r");
if ($h) {
while (!feof($h)) {
$c .= @fread($h, 8192);
}
}
@fclose($h);
return $c;
}
$client = new Snoopy();
$client->agent = MAGPIE_USER_AGENT;
$client->use_gzip = MAGPIE_USE_GZIP;
if ($maxlen) {
$client->maxlength = $maxlen;
}
@ $client->fetch($url);
return $client->results;
}
/**
* Feed Autodiscovery
*
* returns an array of all (hopefully) rss/atom/rdf feeds in the document,
* pointed by $url.
* See http://diveintomark.org/archives/2002/06/02/important_change_to_the_link_tag
*
* @param string $url URL of a web document containing <link> elements
* @return array Array of feed URLs
*/
function extractFeeds($url) {
$cnt = getUrl($url);
$ret = array ();
//find all link tags
if (preg_match_all('|<link\s+\w*=["\'][^"\']+["\']+[^>]*>|Uis', $cnt, $res)) {
while (list ($id, $match) = each($res[0])) {
// we only want '<link alternate=...'
if (strpos(strtolower($match), 'alternate') &&
!strpos(strtolower($match), 'stylesheet') && // extract the attributes
preg_match_all('|([a-zA-Z]*)=["\']([^"\']*)|', $match, $res2, PREG_SET_ORDER)) {
$tmp = array ();
//populate the return array: attr_name => attr_value
while (list ($id2, $match2) = each($res2)) {
$attr = strtolower(trim($match2[1]));
$val = trim($match2[2]);
// make sure we have absolute URI's
if (($attr == "href") && strcasecmp(substr($val, 0, 4), "http") != 0) {
// Check to see if the relative url starts with "//"
if(substr($val,0,2) == "//") {
$val = preg_replace('/\/\/.*/', $val, $url);
} else {
$urlParts = parse_url($url);
if ($urlParts && is_array($urlParts) && strlen($val)) {
if ($val[0] != '/') {
$val = '/'.$val;
}
$val = $urlParts['scheme'] . '://'
.$urlParts['host'] . $val;
} else {
$val = ($url.$val);
}
}
}
$tmp[$attr] = $val;
}
$ret[] = $tmp;
}
}
}
return $ret;
}
PHP 代码:
$url = 'http://ulysses.cn/';
$feeds = extractFeeds($url);
if (!is_array($feeds) || sizeof($feeds) == 0) {
} else {
//if (is_array($feeds) && sizeof($feeds) == 1 && array_key_exists('href',$feeds[0])) {
//echo $feeds[0]['href'] . '<br />';
//} else {
$cnt = 0;
while(list($id, $feedarr) = each($feeds)) {
// we need an URL
if (!array_key_exists('href', $feedarr)) {
continue;
} else {
$href = $feedarr['href'];
}
if (array_key_exists('type', $feedarr)) {
$typeLbl = " [<a href=\"$href\">" . $feedarr['type'] . "</a>]";
}
$cnt++;
if (array_key_exists('title', $feedarr)) {
$lbl = $feedarr['title'];
} elseif (array_key_exists('type', $feedarr)) {
$lbl = $feedarr['type'];
$typeLbl = "";
} elseif (array_key_exists('href', $feedarr)) {
$lbl = $feedarr['href'];
} else {
$lbl = "Resource $cnt";
}
echo "<p>\n\t<input class=\"indent\" type=\"radio\" id=\"fd_$cnt\" name=\"new_channel\" "
." value=\"$href\" />\n"
."\t<label for=\"fd_$cnt\">$lbl $typeLbl</label>\n"
."</p>\n";
//}
}
}
PHP 代码:
function get_list_of_rss($link_id) {
global $wpdb;
$feed = $wpdb->get_row("SELECT link_name, link_url, link_description, link_updated, link_rss FROM `$wpdb->links` WHERE link_id = '$link_id'");
if (!$feed) {
return;
} else {
$link_rss = $feed->link_rss;
$link_name = $feed->link_name;
_e('<h2 class="pagetitle">' . $link_name . '</h2>');
}
$rss = @fetch_rss($link_rss);
if ( isset($rss->items) && 0 != count($rss->items) ) {
_e('<div class="post">');
$rss->items = array_slice($rss->items, 0, count($rss->items));
foreach ($rss->items as $item ) {
?>
<h4><a href='<?php echo wp_filter_kses($item['link']); ?>'><?php echo wp_specialchars($item['title']); ?></a> — <?php printf(__('%s ago'), human_time_diff(strtotime($item['pubdate'], time() ) ) ); ?></h4>
<p><?php echo $item['description']; ?></p>
<?php
}
_e('</div>');
}
}
PHP 代码:
$link_id = (int) $_GET['link_id'];
get_list_of_rss($link_id);
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