<?php
/**
* @copyright Copyright (C) 2020, Friendica
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*/
namespace Friendica\Util;
use DOMDocument;
use DOMXPath;
use Friendica\Content\OEmbed;
use Friendica\Core\Hook;
use Friendica\Core\Logger;
use Friendica\Database\DBA;
use Friendica\DI;
/**
* Get information about a given URL
*
* Class with methods for extracting certain content from an url
*/
class ParseUrl
{
/**
* Maximum number of characters for the description
*/
const MAX_DESC_COUNT = 250;
/**
* Minimum number of characters for the description
*/
const MIN_DESC_COUNT = 100;
/**
* Search for chached embeddable data of an url otherwise fetch it
*
* @param string $url The url of the page which should be scraped
* @param bool $no_guessing If true the parse doens't search for
* preview pictures
* @param bool $do_oembed The false option is used by the function fetch_oembed()
* to avoid endless loops
*
* @return array which contains needed data for embedding
* string 'url' => The url of the parsed page
* string 'type' => Content type
* string 'title' => (optional) The title of the content
* string 'text' => (optional) The description for the content
* string 'image' => (optional) A preview image of the content (only available if $no_geuessing = false)
* array 'images' => (optional) Array of preview pictures
* string 'keywords' => (optional) The tags which belong to the content
*
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
* @see ParseUrl::getSiteinfo() for more information about scraping
* embeddable content
*/
public static function getSiteinfoCached($url, $no_guessing = false, $do_oembed = true)
{
if ($url == "") {
return false;
}
$parsed_url = DBA::selectFirst('parsed_url', ['content'],
['url' => Strings::normaliseLink($url), 'guessing' => !$no_guessing, 'oembed' => $do_oembed]
);
if (!empty($parsed_url['content'])) {
$data = unserialize($parsed_url['content']);
return $data;
}
$data = self::getSiteinfo($url, $no_guessing, $do_oembed);
DBA::insert(
'parsed_url',
[
'url' => substr(Strings::normaliseLink($url), 0, 255), 'guessing' => !$no_guessing,
'oembed' => $do_oembed, 'content' => serialize($data),
'created' => DateTimeFormat::utcNow()
],
true
);
return $data;
}
/**
* Parse a page for embeddable content information
*
* This method parses to url for meta data which can be used to embed
* the content. If available it prioritizes Open Graph meta tags.
* If this is not available it uses the twitter cards meta tags.
* As fallback it uses standard html elements with meta informations
* like \<title\>Awesome Title\</title\> or
* \<meta name="description" content="An awesome description"\>
*
* @param string $url The url of the page which should be scraped
* @param bool $no_guessing If true the parse doens't search for
* preview pictures
* @param bool $do_oembed The false option is used by the function fetch_oembed()
* to avoid endless loops
* @param int $count Internal counter to avoid endless loops
*
* @return array which contains needed data for embedding
* string 'url' => The url of the parsed page
* string 'type' => Content type
* string 'title' => (optional) The title of the content
* string 'text' => (optional) The description for the content
* string 'image' => (optional) A preview image of the content (only available if $no_guessing = false)
* array 'images' => (optional) Array of preview pictures
* string 'keywords' => (optional) The tags which belong to the content
*
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
* @todo https://developers.google.com/+/plugins/snippet/
* @verbatim
* <meta itemprop="name" content="Awesome title">
* <meta itemprop="description" content="An awesome description">
* <meta itemprop="image" content="http://maple.libertreeproject.org/images/tree-icon.png">
*
* <body itemscope itemtype="http://schema.org/Product">
* <h1 itemprop="name">Shiny Trinket</h1>
* <img itemprop="image" src="{image-url}" />
* <p itemprop="description">Shiny trinkets are shiny.</p>
* </body>
* @endverbatim
*/
public static function getSiteinfo($url, $no_guessing = false, $do_oembed = true, $count = 1)
{
// Check if the URL does contain a scheme
$scheme = parse_url($url, PHP_URL_SCHEME);
if ($scheme == '') {
$url = 'http://' . ltrim($url, '/');
}
$url = trim($url, "'\"");
$url = Network::stripTrackingQueryParams($url);
$siteinfo = [
'url' => $url,
'type' => 'link',
];
if ($count > 10) {
Logger::log('Endless loop detected for ' . $url, Logger::DEBUG);
return $siteinfo;
}
$curlResult = DI::httpRequest()->get($url);
if (!$curlResult->isSuccess()) {
return $siteinfo;
}
// If the file is too large then exit
if (($curlResult->getInfo()['download_content_length'] ?? 0) > 1000000) {
return $siteinfo;
}
// If it isn't a HTML file then exit
if (($curlResult->getContentType() != '') && !strstr(strtolower($curlResult->getContentType()), 'html')) {
return $siteinfo;
}
$header = $curlResult->getHeader();
$body = $curlResult->getBody();
if ($do_oembed) {
$oembed_data = OEmbed::fetchURL($url);
if (!empty($oembed_data->type)) {
if (!in_array($oembed_data->type, ['error', 'rich', ''])) {
$siteinfo['type'] = $oembed_data->type;
}
// See https://github.com/friendica/friendica/pull/5763#discussion_r217913178
if ($siteinfo['type'] != 'photo') {
if (isset($oembed_data->title)) {
$siteinfo['title'] = trim($oembed_data->title);
}
if (isset($oembed_data->description)) {
$siteinfo['text'] = trim($oembed_data->description);
}
if (isset($oembed_data->thumbnail_url)) {
$siteinfo['image'] = $oembed_data->thumbnail_url;
}
}
}
}
// Fetch the first mentioned charset. Can be in body or header
$charset = '';
if (preg_match('/charset=(.*?)[\'"\s\n]/', $header, $matches)) {
$charset = trim(trim(trim(array_pop($matches)), ';,'));
}
if ($charset && strtoupper($charset) != 'UTF-8') {
// See https://github.com/friendica/friendica/issues/5470#issuecomment-418351211
$charset = str_ireplace('latin-1', 'latin1', $charset);
Logger::log('detected charset ' . $charset, Logger::DEBUG);
$body = iconv($charset, 'UTF-8//TRANSLIT', $body);
}
$body = mb_convert_encoding($body, 'HTML-ENTITIES', 'UTF-8');
$doc = new DOMDocument();
@$doc->loadHTML($body);
XML::deleteNode($doc, 'style');
XML::deleteNode($doc, 'script');
XML::deleteNode($doc, 'option');
XML::deleteNode($doc, 'h1');
XML::deleteNode($doc, 'h2');
XML::deleteNode($doc, 'h3');
XML::deleteNode($doc, 'h4');
XML::deleteNode($doc, 'h5');
XML::deleteNode($doc, 'h6');
XML::deleteNode($doc, 'ol');
XML::deleteNode($doc, 'ul');
$xpath = new DOMXPath($doc);
$list = $xpath->query('//meta[@content]');
foreach ($list as $node) {
$meta_tag = [];
if ($node->attributes->length) {
foreach ($node->attributes as $attribute) {
$meta_tag[$attribute->name] = $attribute->value;
}
}
if (@$meta_tag['http-equiv'] == 'refresh') {
$path = $meta_tag['content'];
$pathinfo = explode(';', $path);
$content = '';
foreach ($pathinfo as $value) {
if (substr(strtolower($value), 0, 4) == 'url=') {
$content = substr($value, 4);
}
}
if ($content != '') {
$siteinfo = self::getSiteinfo($content, $no_guessing, $do_oembed, ++$count);
return $siteinfo;
}
}
}
$list = $xpath->query('//title');
if ($list->length > 0) {
$siteinfo['title'] = trim($list->item(0)->nodeValue);
}
$list = $xpath->query('//meta[@name]');
foreach ($list as $node) {
$meta_tag = [];
if ($node->attributes->length) {
foreach ($node->attributes as $attribute) {
$meta_tag[$attribute->name] = $attribute->value;
}
}
if (empty($meta_tag['content'])) {
continue;
}
$meta_tag['content'] = trim(html_entity_decode($meta_tag['content'], ENT_QUOTES, 'UTF-8'));
switch (strtolower($meta_tag['name'])) {
case 'fulltitle':
$siteinfo['title'] = trim($meta_tag['content']);
break;
case 'description':
$siteinfo['text'] = trim($meta_tag['content']);
break;
case 'thumbnail':
$siteinfo['image'] = $meta_tag['content'];
break;
case 'twitter:image':
$siteinfo['image'] = $meta_tag['content'];
break;
case 'twitter:image:src':
$siteinfo['image'] = $meta_tag['content'];
break;
case 'twitter:card':
// Detect photo pages
if ($meta_tag['content'] == 'summary_large_image') {
$siteinfo['type'] = 'photo';
}
break;
case 'twitter:description':
$siteinfo['text'] = trim($meta_tag['content']);
break;
case 'twitter:title':
$siteinfo['title'] = trim($meta_tag['content']);
break;
case 'dc.title':
$siteinfo['title'] = trim($meta_tag['content']);
break;
case 'dc.description':
$siteinfo['text'] = trim($meta_tag['content']);
break;
case 'keywords':
$keywords = explode(',', $meta_tag['content']);
break;
case 'news_keywords':
$keywords = explode(',', $meta_tag['content']);
break;
}
}
if (isset($keywords)) {
$siteinfo['keywords'] = [];
foreach ($keywords as $keyword) {
if (!in_array(trim($keyword), $siteinfo['keywords'])) {
$siteinfo['keywords'][] = trim($keyword);
}
}
}
$list = $xpath->query('//meta[@property]');
foreach ($list as $node) {
$meta_tag = [];
if ($node->attributes->length) {
foreach ($node->attributes as $attribute) {
$meta_tag[$attribute->name] = $attribute->value;
}
}
if (!empty($meta_tag['content'])) {
$meta_tag['content'] = trim(html_entity_decode($meta_tag['content'], ENT_QUOTES, 'UTF-8'));
switch (strtolower($meta_tag['property'])) {
case 'og:image':
$siteinfo['image'] = $meta_tag['content'];
break;
case 'og:title':
$siteinfo['title'] = trim($meta_tag['content']);
break;
case 'og:description':
$siteinfo['text'] = trim($meta_tag['content']);
break;
}
}
}
// Prevent to have a photo type without an image
if ((empty($siteinfo['image']) || !empty($siteinfo['text'])) && ($siteinfo['type'] == 'photo')) {
$siteinfo['type'] = 'link';
}
if (!empty($siteinfo['image'])) {
$src = self::completeUrl($siteinfo['image'], $url);
unset($siteinfo['image']);
$photodata = Images::getInfoFromURLCached($src);
if (($photodata) && ($photodata[0] > 10) && ($photodata[1] > 10)) {
$siteinfo['images'][] = ['src' => $src,
'width' => $photodata[0],
'height' => $photodata[1]];
}
}
if (!empty($siteinfo['text']) && mb_strlen($siteinfo['text']) > self::MAX_DESC_COUNT) {
$siteinfo['text'] = mb_substr($siteinfo['text'], 0, self::MAX_DESC_COUNT) . '…';
$pos = mb_strrpos($siteinfo['text'], '.');
if ($pos > self::MIN_DESC_COUNT) {
$siteinfo['text'] = mb_substr($siteinfo['text'], 0, $pos + 1);
}
}
Logger::info('Siteinfo fetched', ['url' => $url, 'siteinfo' => $siteinfo]);
Hook::callAll('getsiteinfo', $siteinfo);
return $siteinfo;
}
/**
* Convert tags from CSV to an array
*
* @param string $string Tags
* @return array with formatted Hashtags
*/
public static function convertTagsToArray($string)
{
$arr_tags = str_getcsv($string);
if (count($arr_tags)) {
// add the # sign to every tag
array_walk($arr_tags, ["self", "arrAddHashes"]);
return $arr_tags;
}
}
/**
* Add a hasht sign to a string
*
* This method is used as callback function
*
* @param string $tag The pure tag name
* @param int $k Counter for internal use
* @return void
*/
private static function arrAddHashes(&$tag, $k)
{
$tag = "#" . $tag;
}
/**
* Add a scheme to an url
*
* The src attribute of some html elements (e.g. images)
* can miss the scheme so we need to add the correct
* scheme
*
* @param string $url The url which possibly does have
* a missing scheme (a link to an image)
* @param string $scheme The url with a correct scheme
* (e.g. the url from the webpage which does contain the image)
*
* @return string The url with a scheme
*/
private static function completeUrl($url, $scheme)
{
$urlarr = parse_url($url);
// If the url does allready have an scheme
// we can stop the process here
if (isset($urlarr["scheme"])) {
return($url);
}
$schemearr = parse_url($scheme);
$complete = $schemearr["scheme"]."://".$schemearr["host"];
if (!empty($schemearr["port"])) {
$complete .= ":".$schemearr["port"];
}
if (!empty($urlarr["path"])) {
if (strpos($urlarr["path"], "/") !== 0) {
$complete .= "/";
}
$complete .= $urlarr["path"];
}
if (!empty($urlarr["query"])) {
$complete .= "?".$urlarr["query"];
}
if (!empty($urlarr["fragment"])) {
$complete .= "#".$urlarr["fragment"];
}
return($complete);
}
}