<?php
class FeedAggregator
{
public $directory;
protected $feeds = array();
public function __construct($directory = 'feeds')
{
$this->setDirectory($directory);
}
public function setDirectory($directory)
{
$this->directory = $directory;
foreach (glob($this->directory .'/*.xml') as $feed) {
$this->feeds[basename($feed, '.xml')] = filemtime($feed);
}
}
public function url2name($url)
{
return preg_replace('/[^\w\.-]+/', '_', $url);
}
public function hasFeed($url)
{
return isset($this->feeds[$this->url2name($url)]);
}
public function addFeed($url)
{
$r = $this->setupRequest($url);
$r->send();
$this->handleResponse($r);
}
public function addFeeds($urls)
{
$pool = new HttpRequestPool;
foreach ($urls as $url) {
$pool->attach($r = $this->setupRequest($url));
}
$pool->send();
foreach ($pool as $request) {
$this->handleResponse($request);
}
}
public function getFeed($url)
{
$this->addFeed($url);
return $this->loadFeed($this->url2name($url));
}
public function getFeeds($urls)
{
$feeds = array();
$this->addFeeds($urls);
foreach ($urls as $url) {
$feeds[] = $this->loadFeed($this->url2name($url));
}
return $feeds;
}
protected function saveFeed($file, $contents)
{
if (file_put_contents($this->directory .'/'. $file .'.xml', $contents)) {
$this->feeds[$file] = time();
} else {
throw new Exception("Could not save feed contents to $file.xml");
}
}
protected function loadFeed($file)
{
if (isset($this->feeds[$file])) {
if ($data = file_get_contents($this->directory .'/'. $file .'.xml')) {
return $data;
} else {
throw new Exception("Could not load feed contents from $file.xml");
}
} else {
throw new Exception("Unknown feed/file $file.xml");
}
}
protected function setupRequest($url)
{
$r = new HttpRequest($url);
$r->setOptions(array('redirect' => true));
$file = $this->url2name($url);
if (isset($this->feeds[$file])) {
$r->setOptions(array('lastmodified' => $this->feeds[$file]));
}
return $r;
}
protected function handleResponse(HttpRequest $r)
{
if ($r->getResponseCode() != 304) {
if ($r->getResponseCode() != 200) {
throw new Exception("Unexpected response code ". $r->getResponseCode());
}
if (!strlen($body = $r->getResponseBody())) {
throw new Exception("Received empty feed from ". $r->getUrl());
}
$this->saveFeed($this->url2name($r->getUrl()), $body);
}
}
}
?>
