<?php
/*
* Copyright (C) 2013 - Rasmus Fuhse <fuhse@data-quest.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*/
/**
* A model class to handle the database table "opengraphdata", fetch data from
* an Opengraph-URL and render a fitting box with the opengraph information to
* the user.
* @property string url database column
* @property string id alias column for url
* @property string is_opengraph database column
* @property string title database column
* @property string image database column
* @property string description database column
* @property string type database column
* @property string data database column
* @property string last_update database column
* @property string chdate database column
* @property string mkdate database column
*/
class OpenGraphURL extends SimpleORMap
{
const EXPIRES_DURATION = 86400; // = 24 * 60 * 60
/**
* Configures this model.
*
* @param Array $config Configuration array
*/
protected static function configure($config = [])
{
$config['db_table'] = 'opengraphdata';
$config['serialized_fields']['data'] = 'JSONArrayObject';
parent::configure($config);
}
/**
* Create an instance of this model given url. Differs from findOneByURL
* insofar that it will return a new object with the given url set
* instead of null.
*
* @param String $url URL to find
* @return OpenGraphURL Either existing instance or a new instance for
* the given url
*/
public static function fromURL($url)
{
$og = self::findOneByUrl($url);
if (!$og) {
$og = new self();
$og->url = $url;
}
return $og;
}
/**
* Specialized findOneByURL function that uses the hash to find the
* appropriate record instead.
*
* @param string $url URL to find record for
* @return mixed instance of OpenGraphURL if available, null otherwise
*/
public static function findOneByURL($url)
{
return self::findOneByHash(md5($url));
}
/**
* Constructor of the object. Provides a fallback if a url is passed
* instead of the usually expected numeric id in order to not break
* backward compatibility.
* But this constructor will fail miserably if a url is passed that
* is not in the database. This was chosen by design to encourage the
* correct use of an id.
*
* @param mixed $id Numeric id, existing url or null
*/
public function __construct($id = null)
{
// Try to find matching id when an url is passed instead of an id.
// This is to ensure that no legacy code will immediately break.
if ($id !== null && !ctype_digit($id)) {
$temp = self::findOneByUrl($id);
if ($temp) {
$id = $temp->id;
}
}
parent::__construct($id);
}
/**
* Sets value of a column. Overwritten so that the hash is also set when
* the url is set.
*
* @param string $field
* @param string $value
* @return string
* @see SimpleORMap::setValue
*/
public function setValue($field, $value)
{
$ret = parent::setValue($field, $value);
if ($field === 'url') {
$this->content['hash'] = md5($value);
}
return $ret;
}
/**
* Stores the object and fetches the opengraph information when either
* the object is new or outdated.
*
* @return int Number of updated records
*/
public function store()
{
if ($this->isNew() || $this->last_update < time() - self::EXPIRES_DURATION) {
// Store last update timestamp BEFORE fetching so another thread
// will not fetch again
$this->last_update = time();
parent::store();
$this->fetch();
}
return parent::store();
}
/**
* Fetches information from the url by getting the contents of the
* webpage, parse the webpage and extract the information from the
* opengraph meta-tags.
* If the site doesn't have any opengraph-metatags it is in fact no
* opengraph node and thus no data will be stored in the database.
* Only $url['is_opengraph'] === '0' indicates that the site is no
* opengraph node at all.
*
* @todo The combination of FileManager::fetchURLMetadata() and the following request
* leads to two requests for the open graph data. This should
* be fixed due to performance reasons.
*/
public function fetch()
{
if (!Config::get()->OPENGRAPH_ENABLE) {
return;
}
$isOpenGraph = false;
$response = FileManager::fetchURLMetadata($this['url']);
if ((int)$response['response_code'] === 200 && isset($response['Content-Type']) && mb_strpos($response['Content-Type'],'html') !== false) {
if (preg_match('/(?<=charset=)[^;]*/i', $response['Content-Type'], $match)) {
$currentEncoding = trim($match[0], '"');
} else {
$currentEncoding = 'UTF-8';
}
$context = get_default_http_stream_context($this['url']);
stream_context_set_option($context, [
'http' => [
'method' => 'GET',
'header' => sprintf("User-Agent: Stud.IP v%s OpenGraph Parser\r\n", $GLOBALS['SOFTWARE_VERSION']),
],
]);
$content = @file_get_contents($this['url'], false, $context);
if ($content === false) {
return;
}
$content = mb_encode_numericentity($content, [0x80, 0xffff, 0, 0xffff], $currentEncoding);
$old_libxml_error = libxml_use_internal_errors(true);
$doc = new DOMDocument();
$doc->loadHTML($content);
libxml_use_internal_errors($old_libxml_error);
$metatags = $doc->getElementsByTagName('meta');
$reservedTags = ['url', 'chdate', 'mkdate', 'last_update', 'is_opengraph', 'data'];
$ogTags = [];
$data = [];
foreach ($metatags as $tag) {
$key = false;
if ($tag->hasAttribute('property')
&& mb_strpos($tag->getAttribute('property'), 'og:') === 0)
{
$key = mb_strtolower(mb_substr($tag->getAttribute('property'), 3));
}
if (!$key && $tag->hasAttribute('name')
&& mb_strpos($tag->getAttribute('name'), 'og:') === 0)
{
$key = mb_strtolower(mb_substr($tag->getAttribute('name'), 3));
}
if ($key) {
$content = $tag->getAttribute('content');
$data[] = ['og:'.$key => $content];
$ogTags[$key] = $content;
$isOpenGraph = true;
}
}
foreach ($ogTags as $key => $tag) {
if ($this->isField($key) && !in_array($key, $reservedTags)) {
$this[$key] = $tag;
}
}
if (empty($this['title']) && $isOpenGraph) {
$titles = $doc->getElementsByTagName('title');
if ($titles->length > 0) {
$this['title'] = $titles->item(0)->textContent;
}
}
if (empty($this['description']) && $isOpenGraph) {
foreach ($metatags as $tag) {
if (mb_stripos($tag->getAttribute('name'), "description") !== false
|| mb_stripos($tag->getAttribute('property'), "description") !== false)
{
$this['description'] = $tag->getAttribute('content');
}
}
}
$this['data'] = $data;
}
$this['is_opengraph'] = (int) $isOpenGraph;
}
/**
* Renders a small box with the information of the opengraph url. Used in
* blubber and in the forum.
*
* @return string html output of the box.
*/
public function render()
{
if (!Config::get()->OPENGRAPH_ENABLE || !$this->getValue('is_opengraph')) {
return '';
}
$template = $GLOBALS['template_factory']->open('shared/opengraphinfo_wide.php');
$template->og = $this;
return $template->render();
}
/**
* Returns an array with all audiofiles that are provided by the opengraph-node.
* Each array-entry is an array itself with the url as first parameter and the
* content-type (important for <audio/> tags) as the second.
*
* @return array(array($url, $content_type), ...)
*/
public function getAudioFiles()
{
return $this->getMediaFiles('audio');
}
/**
* Returns an array with all videofiles that are provided by the opengraph-node.
* Each array-entry is an array itself with the url as first parameter and the
* content-type (important for <video/> tags) as the second.
*
* @return array(array($url, $content_type), ...)
*/
public function getVideoFiles()
{
return $this->getMediaFiles('video');
}
/**
* Returns an array with all mediafiles that are provided by the opengraph-node.
* Each array-entry is an array itself with the url as first parameter and the
* content-type (important for <audio/> or <video/> tags) as the second.
*
* @param string $type "audio" or "video"
* @return array(array($url, $content_type), ...)
*/
protected function getMediaFiles($type)
{
$files = [];
$media = [];
$secure_media = [];
$media_types = [];
foreach ($this['data'] as $meta) {
foreach ($meta as $key => $value) {
switch ($key) {
case "og:{$type}:url":
case "og:{$type}":
$media[] = $value;
break;
case "og:{$type}:secure_url":
$secure_media[] = $value;
break;
case "og:{$type}:type":
$media_types[] = $value;
break;
}
}
}
if ($_SERVER['HTTPS'] === 'on' && count($secure_media) > 0) {
foreach ($secure_media as $index => $url) {
$files[] = [$url, $media_types[$index]];
}
} else {
foreach ($media as $index => $url) {
$files[] = [$url, $media_types[$index]];
}
}
return $files;
}
}