Rss-Bridge/lib/FeedExpander.php

<?php
require_once(__DIR__ . '/BridgeInterface.php');
abstract class FeedExpander extends HttpCachingBridgeAbstract {

  private $name;
  private $uri;
  private $description;

    public function collectExpandableDatas($url, $maxItems = -1){
        if(empty($url)){
            $this->returnServerError('There is no $url for this RSS expander');
        }

        $this->debugMessage('Loading from ' . $url);

        /* Notice we do not use cache here on purpose:
         * we want a fresh view of the RSS stream each time
         */
        $content = $this->getContents($url) 
            or $this->returnServerError('Could not request ' . $url);
        $rssContent = simplexml_load_string($content);

        $this->debugMessage('Detecting feed format/version');
        if(isset($rssContent->channel[0])){
            $this->debugMessage('Detected RSS format');
            if(isset($rssContent->item[0])){
                $this->debugMessage('Detected RSS 1.0 format');
                $this->collect_RSS_1_0_data($rssContent, $maxItems);
            } else {
                $this->debugMessage('Detected RSS 0.9x or 2.0 format');
                $this->collect_RSS_2_0_data($rssContent, $maxItems);
            }
        } elseif(isset($rssContent->entry[0])){
            $this->debugMessage('Detected ATOM format');
            $this->collect_ATOM_data($rssContent, $maxItems);
        } else {
            $this->debugMessage('Unknown feed format/version');
            $this->returnServerError('The feed format is unknown!');
        }
    }

    protected function collect_RSS_1_0_data($rssContent, $maxItems){
        $this->load_RSS_2_0_feed_data($rssContent->channel[0]);
        foreach($rssContent->item as $item){
            $this->debugMessage('parsing item ' . var_export($item, true));
            $this->items[] = $this->parseItem($item);
            if($maxItems !== -1 && count($this->items) >= $maxItems) break;
        }
    }

    protected function collect_RSS_2_0_data($rssContent, $maxItems){
        $rssContent = $rssContent->channel[0];
        $this->debugMessage('RSS content is ===========\n' . var_export($rssContent, true) . '===========');
        $this->load_RSS_2_0_feed_data($rssContent);
        foreach($rssContent->item as $item){
            $this->debugMessage('parsing item ' . var_export($item, true));
            $this->items[] = $this->parseItem($item);
            if($maxItems !== -1 && count($this->items) >= $maxItems) break;
        }
    }

    protected function collect_ATOM_data($content, $maxItems){
        $this->load_ATOM_feed_data($content);
        foreach($content->entry as $item){
            $this->debugMessage('parsing item ' . var_export($item, true));
            $this->items[] = $this->parseItem($item);
            if($maxItems !== -1 && count($this->items) >= $maxItems) break;
        }
    }

    protected function RSS_2_0_time_to_timestamp($item){
        return DateTime::createFromFormat('D, d M Y H:i:s e', $item->pubDate)->getTimestamp();
    }

    // TODO set title, link, description, language, and so on
    protected function load_RSS_2_0_feed_data($rssContent){
        $this->name = trim($rssContent->title);
        $this->uri = trim($rssContent->link);
        $this->description = trim($rssContent->description);
    }

    protected function load_ATOM_feed_data($content){
        $this->name = $content->title;

        // Find best link (only one, or first of 'alternate')
        if(!isset($content->link)){
            $this->uri = '';
        } elseif (count($content->link) === 1){
            $this->uri = $content->link[0]['href'];
        } else {
            $this->uri = '';
            foreach($content->link as $link){
                if(strtolower($link['rel']) === 'alternate'){
                    $this->uri = $link['href'];
                    break;
                }
            }
        }

        if(isset($content->subtitle))
            $this->description = $content->subtitle;
    }

    protected function parseATOMItem($feedItem){
        $item = array();
        if(isset($feedItem->id)) $item['uri'] = $feedItem->id;
        if(isset($feedItem->title)) $item['title'] = $feedItem->title;
        if(isset($feedItem->updated)) $item['timestamp'] = strtotime($feedItem->updated);
        if(isset($feedItem->author)) $item['author'] = $feedItem->author->name;
        if(isset($feedItem->content)) $item['content'] = $feedItem->content;
        return $item;
    }

    protected function parseRSS_0_9_1_Item($feedItem){
        $item = array();
        if(isset($feedItem->link)) $item['uri'] = $feedItem->link;
        if(isset($feedItem->title)) $item['title'] = $feedItem->title;
        // rss 0.91 doesn't support timestamps
        // rss 0.91 doesn't support authors
        if(isset($feedItem->description)) $item['content'] = $feedItem->description;
        return $item;
    }

    protected function parseRSS_1_0_Item($feedItem){
        // 1.0 adds optional elements around the 0.91 standard
        $item = $this->parseRSS_0_9_1_Item($feedItem);

        $namespaces = $feedItem->getNamespaces(true);
        if(isset($namespaces['dc'])){
            $dc = $feedItem->children($namespaces['dc']);
            if(isset($dc->date)) $item['timestamp'] = strtotime($dc->date);
            if(isset($dc->creator)) $item['author'] = $dc->creator;
        }

        return $item;
    }

    protected function parseRSS_2_0_Item($feedItem){
        // Primary data is compatible to 0.91 with some additional data
        $item = $this->parseRSS_0_9_1_Item($feedItem);

        $namespaces = $feedItem->getNamespaces(true);
        if(isset($namespaces['dc'])) $dc = $feedItem->children($namespaces['dc']);

        if(isset($feedItem->pubDate)){
            $item['timestamp'] = strtotime($feedItem->pubDate);
        } elseif(isset($dc->date)){
            $item['timestamp'] = strtotime($dc->date);
        }
        if(isset($feedItem->author)){
            $item['author'] = $feedItem->author;
        } elseif(isset($dc->creator)){
            $item['author'] = $dc->creator;
        }
        return $item;
    }

    /**
     * Method should return, from a source RSS item given by lastRSS, one of our Items objects
     * @param $item the input rss item
     * @return a RSS-Bridge Item, with (hopefully) the whole content)
     */
    abstract protected function parseItem($item);

    public function getURI(){
      return $this->uri;
    }

    public function getName(){
      return $this->name;
    }

    public function getDescription(){
        return $this->description;
    }
}