<?php
/**
* @class feedReader
* @brief Feed Reader
*
* Features:
*
* - Reads RSS 1.0 (rdf), RSS 2.0 and Atom feeds.
* - HTTP cache negociation support
* - Cache TTL.
*
* @package Clearbricks
* @subpackage Feeds
*
* @copyright Olivier Meunier & Association Dotclear
* @copyright GPL-2.0-only
*/
/* @cond ONCE */
if (class_exists('netHttp')) {
/** @endcond */
class feedReader extends netHttp
{
protected $user_agent = 'Clearbricks Feed Reader/0.2';
protected $timeout = 5;
protected $validators = null; ///< array HTTP Cache validators
protected $cache_dir = null; ///< string Cache directory path
protected $cache_file_prefix = 'cbfeed'; ///< string Cache file prefix
protected $cache_ttl = '-30 minutes'; ///< string Cache TTL
/**
* Constructor.
*
* Does nothing. See {@link parse()} method for URL handling.
*/
public function __construct()
{
parent::__construct('');
}
/**
* Parse Feed
*
* Returns a new feedParser instance for given URL or false if source URL is
* not a valid feed.
*
* @uses feedParser
*
* @param string $url Feed URL
* @return feedParser|false
*/
public function parse($url)
{
$this->validators = [];
if ($this->cache_dir) {
return $this->withCache($url);
}
if (!$this->getFeed($url)) {
return false;
}
if ($this->getStatus() != '200') {
return false;
}
return new feedParser($this->getContent());
}
/**
* Quick Parse
*
* This static method returns a new {@link feedParser} instance for given URL. If a
* <var>$cache_dir</var> is specified, cache will be activated.
*
* @param string $url Feed URL
* @param string $cache_dir Cache directory
* @return feedParser|false
*/
public static function quickParse($url, $cache_dir = null)
{
$parser = new self();
if ($cache_dir) {
$parser->setCacheDir($cache_dir);
}
return $parser->parse($url);
}
/**
* Set Cache Directory
*
* Returns true and sets {@link $cache_dir} property if <var>$dir</var> is
* a writable directory. Otherwise, returns false.
*
* @param string $dir Cache directory
* @return boolean
*/
public function setCacheDir($dir)
{
$this->cache_dir = null;
if (!empty($dir) && is_dir($dir) && is_writeable($dir)) {
$this->cache_dir = $dir;
return true;
}
return false;
}
/**
* Set Cache TTL
*
* Sets cache TTL. <var>$str</var> is a interval readable by strtotime
* (-3 minutes, -2 hours, etc.)
*
* @param string $str TTL
*/
public function setCacheTTL($str)
{
$str = trim((string) $str);
if (!empty($str)) {
if (substr($str, 0, 1) != '-') {
$str = '-' . $str;
}
$this->cache_ttl = $str;
}
}
/**
* Feed Content
*
* Returns feed content for given URL.
*
* @param string $url Feed URL
* @return string|boolean
*/
protected function getFeed($url)
{
if (!self::readURL($url, $ssl, $host, $port, $path, $user, $pass)) {
return false;
}
$this->setHost($host, $port);
$this->useSSL($ssl);
$this->setAuthorization($user, $pass);
return $this->get($path);
}
/**
* Cache content
*
* Returns feedParser object from cache if present or write it to cache and
* returns result.
*
* @param string $url Feed URL
* @return feedParser|false
*/
protected function withCache($url)
{
$url_md5 = md5($url);
$cached_file = sprintf(
'%s/%s/%s/%s/%s.php',
$this->cache_dir,
$this->cache_file_prefix,
substr($url_md5, 0, 2),
substr($url_md5, 2, 2),
$url_md5
);
$may_use_cached = false;
if (@file_exists($cached_file)) {
$may_use_cached = true;
$ts = @filemtime($cached_file);
if ($ts > strtotime($this->cache_ttl)) {
# Direct cache
return unserialize(file_get_contents($cached_file));
}
$this->setValidator('IfModifiedSince', $ts);
}
if (!$this->getFeed($url)) {
if ($may_use_cached) {
# connection failed - fetched from cache
return unserialize(file_get_contents($cached_file));
}
return false;
}
switch ($this->getStatus()) {
case '304':
@files::touch($cached_file);
return unserialize(file_get_contents($cached_file));
case '200':
$feed = new feedParser($this->getContent());
try {
files::makeDir(dirname($cached_file), true);
} catch (Exception $e) {
return $feed;
}
if (($fp = @fopen($cached_file, 'wb'))) {
fwrite($fp, serialize($feed));
fclose($fp);
files::inheritChmod($cached_file);
}
return $feed;
}
return false;
}
/**
* Build request
*
* Adds HTTP cache headers to common headers.
*
* {@inheritdoc}
*/
protected function buildRequest()
{
$headers = parent::buildRequest();
# Cache validators
if (!empty($this->validators)) {
if (isset($this->validators['IfModifiedSince'])) {
$headers[] = 'If-Modified-Since: ' . $this->validators['IfModifiedSince'];
}
if (isset($this->validators['IfNoneMatch'])) {
if (is_array($this->validators['IfNoneMatch'])) {
$etags = implode(',', $this->validators['IfNoneMatch']);
} else {
$etags = $this->validators['IfNoneMatch'];
}
$headers[] = '';
}
}
return $headers;
}
private function setValidator($key, $value)
{
if ($key == 'IfModifiedSince') {
$value = gmdate('D, d M Y H:i:s', $value) . ' GMT';
}
$this->validators[$key] = $value;
}
}
/* @cond ONCE */
}
/* @endcond */