Rss-Bridge/bridges/FacebookBridge.php
LogMANOriginal 0d80a19e84
[FacebookBridge] Add context for public Facebook groups (#739)
The previous context is now labeled 'User', while the new context is
labeled 'Group'. The existing code was not changed, instead new group*
functions were implemented to handle groups.

The general principle of capturing groups is the same as done for users
with adjustments to account for different HTML structures.

Captcha responses are currently not supported for groups! There doesn't
seem to be a way to trigger them consistently, which makes it hard to
handle them properly.

Features of the group context:

- The feed title is based on the group name
- The group URI used for capturing is returned for the feed URI
- Author names and timestamps are reproduced from the source
- Post titles are reproduced from the source if they exist, otherwise
the title is build manually from the author name and the content
- Original contents are included with the feed
- All images are attached as enclosures as well

Closes #
2018-07-08 17:16:00 +02:00

575 lines
15 KiB
PHP

<?php
class FacebookBridge extends BridgeAbstract {
const MAINTAINER = 'teromene, logmanoriginal';
const NAME = 'Facebook';
const URI = 'https://www.facebook.com/';
const CACHE_TIMEOUT = 300; // 5min
const DESCRIPTION = 'Input a page title or a profile log. For a profile log,
please insert the parameter as follow : myExamplePage/132621766841117';
const PARAMETERS = array(
'User' => array(
'u' => array(
'name' => 'Username',
'required' => true
),
'media_type' => array(
'name' => 'Media type',
'type' => 'list',
'required' => false,
'values' => array(
'All' => 'all',
'Video' => 'video',
'No Video' => 'novideo'
),
'defaultValue' => 'all'
),
'skip_reviews' => array(
'name' => 'Skip reviews',
'type' => 'checkbox',
'required' => false,
'defaultValue' => false,
'title' => 'Feed includes reviews when checked'
)
),
'Group' => array(
'g' => array(
'name' => 'Group',
'type' => 'text',
'required' => true,
'exampleValue' => 'https://www.facebook.com/groups/743149642484225',
'title' => 'Insert group name or facebook group URL'
)
)
);
private $authorName = '';
private $groupName = '';
public function getURI() {
$uri = self::URI;
switch($this->queriedContext) {
case 'Group':
$uri .= 'groups/' . $this->sanitizeGroup(filter_var($this->getInput('g'), FILTER_SANITIZE_URL));
break;
}
return $uri .= '?_fb_noscript=1';
}
public function collectData() {
switch($this->queriedContext) {
case 'Group':
$this->collectGroupData();
break;
case 'User':
$this->collectUserData();
break;
default:
returnClientError('Unknown context: "' . $this->queriedContext . '"!');
}
}
#region Group
private function collectGroupData() {
$header = array('Accept-Language: ' . getEnv('HTTP_ACCEPT_LANGUAGE') . "\r\n");
$html = getSimpleHTMLDOM($this->getURI(), $header)
or returnServerError('Failed loading facebook page: ' . $this->getURI());
if(!$this->isPublicGroup($html)) {
returnClientError('This group is not public! RSS-Bridge only supports public groups!');
}
defaultLinkTo($html, substr(self::URI, 0, strlen(self::URI) - 1));
$this->groupName = $this->extractGroupName($html);
$posts = $html->find('div.userContentWrapper')
or returnServerError('Failed finding posts!');
foreach($posts as $post) {
$item = array();
$item['uri'] = $this->extractGroupURI($post);
$item['title'] = $this->extractGroupTitle($post);
$item['author'] = $this->extractGroupAuthor($post);
$item['content'] = $this->extractGroupContent($post);
$item['timestamp'] = $this->extractGroupTimestamp($post);
$item['enclosures'] = $this->extractGroupEnclosures($post);
$this->items[] = $item;
}
}
private function sanitizeGroup($group) {
if(filter_var(
$group,
FILTER_VALIDATE_URL,
FILTER_FLAG_HOST_REQUIRED | FILTER_FLAG_PATH_REQUIRED)) {
// User provided a URL
$urlparts = parse_url($group);
if($urlparts['host'] !== parse_url(self::URI)['host']
&& 'www.' . $urlparts['host'] !== parse_url(self::URI)['host']) {
returnClientError('The host you provided is invalid! Received "'
. $urlparts['host']
. '", expected "'
. parse_url(self::URI)['host']
. '"!');
}
return explode('/', $urlparts['path'])[2];
} elseif(strpos($group, '/') !== false) {
returnClientError('The group you provided is invalid: ' . $group);
} else {
return $group;
}
}
private function isPublicGroup($html) {
// Facebook redirects to the groups about page for non-public groups
$about = $html->find('#pagelet_group_about', 0);
return !($about);
}
private function extractGroupName($html) {
$ogtitle = $html->find('meta[property="og:title"]', 0)
or returnServerError('Unable to find group title!');
return htmlspecialchars_decode($ogtitle->content, ENT_QUOTES);
}
private function extractGroupURI($post) {
$elements = $post->find('a')
or returnServerError('Unable to find URI!');
foreach($elements as $anchor) {
// Find the one that is a permalink
if(strpos($anchor->href, 'permalink') !== false) {
return $anchor->href;
}
}
return null;
}
private function extractGroupContent($post) {
$content = $post->find('div.userContent', 0)
or returnServerError('Unable to find user content!');
return $content->innertext . $content->next_sibling()->innertext;
}
private function extractGroupTimestamp($post) {
$element = $post->find('abbr[data-utime]', 0)
or returnServerError('Unable to find timestamp!');
return $element->getAttribute('data-utime');
}
private function extractGroupAuthor($post) {
$element = $post->find('img', 0)
or returnServerError('Unable to find author information!');
return $element->{'aria-label'};
}
private function extractGroupEnclosures($post) {
$elements = $post->find('div.userContent', 0)->next_sibling()->find('img');
$enclosures = array();
foreach($elements as $enclosure) {
$enclosures[] = $enclosure->src;
}
return empty($enclosures) ? null : $enclosures;
}
private function extractGroupTitle($post) {
$element = $post->find('h5', 0)
or returnServerError('Unable to find title!');
if(strpos($element->plaintext, 'shared') === false) {
$content = strip_tags($this->extractGroupContent($post));
return $this->extractGroupAuthor($post)
. ' posted: '
. substr(
$content,
0,
strpos(wordwrap($content, 64), "\n")
)
. '...';
}
return $element->plaintext;
}
#endregion
private function collectUserData(){
//Extract a string using start and end delimiters
function extractFromDelimiters($string, $start, $end){
if(strpos($string, $start) !== false) {
$section_retrieved = substr($string, strpos($string, $start) + strlen($start));
$section_retrieved = substr($section_retrieved, 0, strpos($section_retrieved, $end));
return $section_retrieved;
}
return false;
}
//Utility function for cleaning a Facebook link
$unescape_fb_link = function($matches){
if(is_array($matches) && count($matches) > 1) {
$link = $matches[1];
if(strpos($link, '/') === 0)
$link = self::URI . $link;
if(strpos($link, 'facebook.com/l.php?u=') !== false)
$link = urldecode(extractFromDelimiters($link, 'facebook.com/l.php?u=', '&'));
return ' href="' . $link . '"';
}
};
//Utility function for converting facebook emoticons
$unescape_fb_emote = function($matches){
static $facebook_emoticons = array(
'smile' => ':)',
'frown' => ':(',
'tongue' => ':P',
'grin' => ':D',
'gasp' => ':O',
'wink' => ';)',
'pacman' => ':<',
'grumpy' => '>_<',
'unsure' => ':/',
'cry' => ':\'(',
'kiki' => '^_^',
'glasses' => '8-)',
'sunglasses' => 'B-)',
'heart' => '<3',
'devil' => ']:D',
'angel' => '0:)',
'squint' => '-_-',
'confused' => 'o_O',
'upset' => 'xD',
'colonthree' => ':3',
'like' => '&#x1F44D;');
$len = count($matches);
if ($len > 1)
for ($i = 1; $i < $len; $i++)
foreach ($facebook_emoticons as $name => $emote)
if ($matches[$i] === $name)
return $emote;
return $matches[0];
};
$html = null;
//Handle captcha response sent by the viewer
if (isset($_POST['captcha_response'])) {
if (session_status() == PHP_SESSION_NONE)
session_start();
if (isset($_SESSION['captcha_fields'], $_SESSION['captcha_action'])) {
$captcha_action = $_SESSION['captcha_action'];
$captcha_fields = $_SESSION['captcha_fields'];
$captcha_fields['captcha_response'] = preg_replace('/[^a-zA-Z0-9]+/', '', $_POST['captcha_response']);
$header = array("Content-type:
application/x-www-form-urlencoded\r\nReferer: $captcha_action\r\nCookie: noscript=1\r\n");
$opts = array(
CURLOPT_POST => 1,
CURLOPT_POSTFIELDS => http_build_query($captcha_fields)
);
$html = getContents($captcha_action, $header, $opts);
if($html === false) {
returnServerError('Failed to submit captcha response back to Facebook');
}
unset($_SESSION['captcha_fields']);
$html = str_get_html($html);
}
unset($_SESSION['captcha_fields']);
unset($_SESSION['captcha_action']);
}
//Retrieve page contents
if(is_null($html)) {
$header = array('Accept-Language: ' . getEnv('HTTP_ACCEPT_LANGUAGE') . "\r\n");
// Check if the user provided a fully qualified URL
if (filter_var($this->getInput('u'), FILTER_VALIDATE_URL)) {
$urlparts = parse_url($this->getInput('u'));
if($urlparts['host'] !== parse_url(self::URI)['host']) {
returnClientError('The host you provided is invalid! Received "'
. $urlparts['host']
. '", expected "'
. parse_url(self::URI)['host']
. '"!');
}
if(!array_key_exists('path', $urlparts)
|| $urlparts['path'] === '/') {
returnClientError('The URL you provided doesn\'t contain the user name!');
}
$user = explode('/', $urlparts['path'])[1];
$html = getSimpleHTMLDOM(self::URI . urlencode($user) . '?_fb_noscript=1', $header)
or returnServerError('No results for this query.');
} else {
// First character cannot be a forward slash
if(strpos($this->getInput('u'), '/') === 0) {
returnClientError('Remove leading slash "/" from the username!');
}
if(!strpos($this->getInput('u'), '/')) {
$html = getSimpleHTMLDOM(self::URI . urlencode($this->getInput('u')) . '?_fb_noscript=1', $header)
or returnServerError('No results for this query.');
} else {
$html = getSimpleHTMLDOM(self::URI . 'pages/' . $this->getInput('u') . '?_fb_noscript=1', $header)
or returnServerError('No results for this query.');
}
}
}
//Handle captcha form?
$captcha = $html->find('div.captcha_interstitial', 0);
if (!is_null($captcha)) {
//Save form for submitting after getting captcha response
if (session_status() == PHP_SESSION_NONE)
session_start();
$captcha_fields = array();
foreach ($captcha->find('input, button') as $input)
$captcha_fields[$input->name] = $input->value;
$_SESSION['captcha_fields'] = $captcha_fields;
$_SESSION['captcha_action'] = $captcha->find('form', 0)->action;
//Show captcha filling form to the viewer, proxying the captcha image
$img = base64_encode(getContents($captcha->find('img', 0)->src));
http_response_code(500);
header('Content-Type: text/html');
$message = <<<EOD
<form method="post" action="?{$_SERVER['QUERY_STRING']}">
<h2>Facebook captcha challenge</h2>
<p>Unfortunately, rss-bridge cannot fetch the requested page.<br />
Facebook wants rss-bridge to resolve the following captcha:</p>
<p><img src="data:image/png;base64,{$img}" /></p>
<p><b>Response:</b> <input name="captcha_response" placeholder="please fill in" />
<input type="submit" value="Submit!" /></p>
</form>
EOD;
die($message);
}
//No captcha? We can carry on retrieving page contents :)
//First, we check wether the page is public or not
$loginForm = $html->find('._585r', 0);
if($loginForm != null) {
returnServerError('You must be logged in to view this page. This is not supported by RSS-Bridge.');
}
$element = $html
->find('#pagelet_timeline_main_column')[0]
->children(0)
->children(0)
->children(0)
->next_sibling()
->children(0);
if(isset($element)) {
$author = str_replace(' | Facebook', '', $html->find('title#pageTitle', 0)->innertext);
$profilePic = 'https://graph.facebook.com/'
. $this->getInput('u')
. '/picture?width=200&amp;height=200';
$this->authorName = $author;
foreach($element->children() as $cell) {
// Manage summary posts
if(strpos($cell->class, '_3xaf') !== false) {
$posts = $cell->children();
} else {
$posts = array($cell);
}
// Optionally skip reviews
if($this->getInput('skip_reviews')
&& !is_null($cell->find('#review_composer_container', 0))) {
continue;
}
foreach($posts as $post) {
// Check media type
switch($this->getInput('media_type')) {
case 'all': break;
case 'video':
if(empty($post->find('[aria-label=Video]'))) continue 2;
break;
case 'novideo':
if(!empty($post->find('[aria-label=Video]'))) continue 2;
break;
default: break;
}
$item = array();
if(count($post->find('abbr')) > 0) {
//Retrieve post contents
$content = preg_replace(
'/(?i)><div class=\"clearfix([^>]+)>(.+?)div\ class=\"userContent\"/i',
'',
$post);
$content = preg_replace(
'/(?i)><div class=\"_59tj([^>]+)>(.+?)<\/div><\/div><a/i',
'',
$content);
$content = preg_replace(
'/(?i)><div class=\"_3dp([^>]+)>(.+?)div\ class=\"[^u]+userContent\"/i',
'',
$content);
$content = preg_replace(
'/(?i)><div class=\"_4l5([^>]+)>(.+?)<\/div>/i',
'',
$content);
//Remove html nodes, keep only img, links, basic formatting
$content = strip_tags($content, '<a><img><i><u><br><p>');
//Adapt link hrefs: convert relative links into absolute links and bypass external link redirection
$content = preg_replace_callback('/ href=\"([^"]+)\"/i', $unescape_fb_link, $content);
//Clean useless html tag properties and fix link closing tags
foreach (array(
'onmouseover',
'onclick',
'target',
'ajaxify',
'tabindex',
'class',
'style',
'data-[^=]*',
'aria-[^=]*',
'role',
'rel',
'id') as $property_name)
$content = preg_replace('/ ' . $property_name . '=\"[^"]*\"/i', '', $content);
$content = preg_replace('/<\/a [^>]+>/i', '</a>', $content);
//Convert textual representation of emoticons eg
//"<i><u>smile emoticon</u></i>" back to ASCII emoticons eg ":)"
$content = preg_replace_callback(
'/<i><u>([^ <>]+) ([^<>]+)<\/u><\/i>/i',
$unescape_fb_emote,
$content
);
//Retrieve date of the post
$date = $post->find('abbr')[0];
if(isset($date) && $date->hasAttribute('data-utime')) {
$date = $date->getAttribute('data-utime');
} else {
$date = 0;
}
//Build title from username and content
$title = $author;
if(strlen($title) > 24)
$title = substr($title, 0, strpos(wordwrap($title, 24), "\n")) . '...';
$title = $title . ' | ' . strip_tags($content);
if(strlen($title) > 64)
$title = substr($title, 0, strpos(wordwrap($title, 64), "\n")) . '...';
$uri = self::URI . $post->find('abbr')[0]->parent()->getAttribute('href');
//Build and add final item
$item['uri'] = htmlspecialchars_decode($uri);
$item['content'] = htmlspecialchars_decode($content);
$item['title'] = $title;
$item['author'] = $author;
$item['timestamp'] = $date;
$this->items[] = $item;
}
}
}
}
}
public function getName(){
switch($this->queriedContext) {
case 'User':
if(!empty($this->authorName)) {
return isset($this->extraInfos['name']) ? $this->extraInfos['name'] : $this->authorName
. ' - Facebook Bridge';
}
break;
case 'Group':
if(!empty($this->groupName)) {
return $this->groupName . ' - Facebook Bridge';
}
break;
}
return parent::getName();
}
}