<?php
/**
* @package VikWP - Libraries
* @subpackage adapter.rss
* @author E4J s.r.l.
* @copyright Copyright (C) 2023 E4J s.r.l. All Rights Reserved.
* @license http://www.gnu.org/licenses/gpl-2.0.html GNU/GPL
* @link https://vikwp.com
*/
// No direct access
defined('ABSPATH') or die('No script kiddies please!');
JLoader::import('adapter.rss.feed');
JLoader::import('adapter.rss.optinexception');
/**
* Helper class used to read the RSS feed provided by VikWP.
*
* @since 10.1.31
*/
class JRssReader
{
/**
* A list of instances.
*
* @var array
*/
protected static $instances = array();
/**
* A list of feed channels (URL).
*
* @var array
*/
protected $channels;
/**
* The name of the callee;
*
* @var string
*/
protected $plugin;
/**
* Returns the singleton of this class.
*
* @param mixed $url Either the feed URL or an array.
* @param string $plugin The plugin that called this class. If not
* specified, it will be taken from the request.
*
* @return self The instance of this object.
*/
public static function getInstance($url, $plugin = null)
{
if (!$plugin)
{
// try to recover plugin name from request if not specified
$plugin = JFactory::getApplication()->input->get('option', 'vikplugin');
}
// serialize arguments
$sign = serialize(func_get_args());
// check whether the instance already exists
if (!isset(static::$instances[$sign]))
{
// instantiate only once
static::$instances[$sign] = new static($url, $plugin);
}
return static::$instances[$sign];
}
/**
* Class constructor.
*
* @param mixed $url Either the feed URL or an array.
* @param string $plugin The plugin that called this class.
*/
protected function __construct($url, $plugin)
{
$this->channels = (array) $url;
$this->plugin = (string) $plugin;
}
/**
* Choose whether to opt in to the RSS feed services.
*
* @param boolean $status True to opt in, false to the decline.
*
* @return self This object to support chaining.
*/
public function optIn($status = true)
{
$user = JFactory::getUser();
if ($user->guest)
{
// throw exception in case of guest user
throw new Exception('Guest users cannot opt-in to the RSS service', 403);
}
if ($status)
{
// register opt-in date
$status = JDate::getInstance()->toSql();
}
else
{
// service declined
$status = 0;
}
// register user choice
update_user_meta($user->id, $this->plugin . '_rss_optin', $status);
return $this;
}
/**
* Checks whether the user opted in the RSS feed services.
*
* @param string $date True to return the opt-in date.
*
* @return mixed $status True if opted in, false if declined.
* A JDate instance in case $date is true.
*
* @throws Exception In case the user didn't decide yet.
*/
public function optedIn($date = false)
{
$user = JFactory::getUser();
if ($user->guest)
{
// ignore choice of guest users
return false;
}
// retrieve user choice
$choice = get_user_meta($user->id, $this->plugin . '_rss_optin', true);
// make sure a choice was made
if ($choice === false || $choice === '')
{
// missing choice, throw exception
throw new JRssOptInException();
}
if ($date && $choice)
{
// return opt-in date
return new JDate($choice);
}
return (bool) $choice;
}
/**
* Returns a list of RSS permalinks.
*
* @return array
*/
public function getChannels()
{
return $this->channels;
}
/**
* Download a list of feeds from the registered channels.
*
* @param array $options A configuration array.
* - start the starting index to take feeds;
* - limit the number of feeds to take;
* - new true to retrieve only feeds never seen;
* - order the sorting mode (asc or desc).
*
* @return JRssFeed[] An array of feeds.
*/
public function download(array $options = array())
{
// get opt-in date
$optinDate = $this->optedIn(true);
// make sure the user opted in the RSS service
if (!$optinDate)
{
// authorization denied, do not go ahead
throw new Exception('Missing RSS authorization', 403);
}
// read feed channels
$feed = fetch_feed($this->channels);
if ($feed instanceof WP_Error)
{
// get SimplePie error
$error = $feed->get_error_message();
// extract first element as long as error is an array
while (is_array($error))
{
$error = array_shift($error);
}
// something went wrong, propagate error
throw new Exception($error, (int) $feed->get_error_code());
}
$list = array();
$start = isset($options['start']) ? abs($options['start']) : 0;
$limit = isset($options['limit']) ? abs($options['limit']) : 0;
// check if we should retrive only the visible feeds
$strict = isset($options['new']) ? (bool) $options['new'] : false;
// check if we should retrieve the feeds in ascending order
$ordering = isset($options['order']) ? strtolower($options['order']) : 'desc';
if ($strict || $ordering == 'asc')
{
// take all the items without limits because
// we need to check whether the feeds are visible
$items = $feed->get_items();
if ($ordering == 'asc')
{
// load items in reverse order from oldest to newest
$items = array_reverse($items);
}
}
else
{
// take the feeds according to the specified limits
$items = $feed->get_items($start, $limit);
}
// iterate multi-feed property to scan all the supported feeds
foreach ($items as $data)
{
// encapsulate feed data
$feed = new JRssFeed($data, $this->plugin);
// check if we should take only visible feeds
if (!$strict || ($feed->isVisible() && $optinDate < $feed->date))
{
// take feed
$list[] = $feed;
}
}
if ($strict)
{
// prepare base arguments for array_splice
$args = array(&$list, $start);
if ($limit)
{
// consider limit only if specified, because
// array_splice take care of the number of
// arguments instead of on their values
$args[] = $limit;
}
// take only the feeds inside the specified range
$list = call_user_func_array('array_splice', $args);
}
if ($limit == 1)
{
// take directly the first element
return array_shift($list);
}
return $list;
}
}