source: inc/core/class.dc.trackback.php @ 270:48858be15bda

<?php
# -- BEGIN LICENSE BLOCK ---------------------------------------
#
# This file is part of Dotclear 2.
#
# Copyright (c) 2003-2011 Olivier Meunier & Association Dotclear
# Licensed under the GPL version 2.0 license.
# See LICENSE file or
# http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
#
# -- END LICENSE BLOCK -----------------------------------------
if (!defined('DC_RC_PATH')) { return; }

/**
@ingroup DC_CORE
@brief Trackbacks sender and server

Sends and receives trackbacks. Also handles trackbacks auto discovery.
*/
class dcTrackback
{
     public $core;       ///< <b>dcCore</b> dcCore instance
     public $table;      ///< <b>string</b> done pings table name
     
     /**
     Object constructor
     
     @param    core      <b>dcCore</b>       dcCore instance
     */
     public function __construct($core)
     {
          $this->core =& $core;
          $this->con =& $this->core->con;
          $this->table = $this->core->prefix.'ping';
     }
     
     /// @name Send trackbacks
     //@{
     /**
     Get all pings sent for a given post.
     
     @param    post_id   <b>integer</b>      Post ID
     @return   <b>record</b>
     */
     public function getPostPings($post_id)
     {
          $strReq = 'SELECT ping_url, ping_dt '.
                    'FROM '.$this->table.' '.
                    'WHERE post_id = '.(integer) $post_id;
          
          return $this->con->select($strReq);
     }
     
     /**
     Sends a ping to given <var>$url</var>.
     
     @param    url            <b>string</b>       URL to ping
     @param    post_id        <b>integer</b>      Post ID
     @param    post_title     <b>string</b>       Post title
     @param    post_excerpt   <b>string</b>       Post excerpt
     @param    post_url       <b>string</b>       Post URL
     */
     public function ping($url,$post_id,$post_title,$post_excerpt,$post_url)
     {
          if ($this->core->blog === null) {
               return false;
          }
          
          $post_id = (integer) $post_id;
          
          # Check for previously done trackback
          $strReq = 'SELECT post_id, ping_url FROM '.$this->table.' '.
                    'WHERE post_id = '.$post_id.' '.
                    "AND ping_url = '".$this->con->escape($url)."' ";
          
          $rs = $this->con->select($strReq);
          
          if (!$rs->isEmpty()) {
               throw new Exception(sprintf(__('%s has still been pinged'),$url));
          }
          
          $data = array(
               'title' => $post_title,
               'excerpt' => $post_excerpt,
               'url' => $post_url,
               'blog_name' => trim(html::escapeHTML(html::clean($this->core->blog->name)))
               //,'__debug' => false
          );
          
          # Ping
          try
          {
               $http = self::initHttp($url,$path);
               $http->post($path,$data,'UTF-8');
               $res = $http->getContent();
          }
          catch (Exception $e)
          {
               throw new Exception(__('Unable to ping URL'));
          }
          
          $pattern =
          '|<response>.*<error>(.*)</error>(.*)'.
          '(<message>(.*)</message>(.*))?'.
          '</response>|msU';
          
          if (!preg_match($pattern,$res,$match))
          {
               throw new Exception(sprintf(__('%s is not a ping URL'),$url));
          }
          
          $ping_error = trim($match[1]);
          $ping_msg = (!empty($match[4])) ? $match[4] : '';
          
          if ($ping_error != '0') {
               throw new Exception(sprintf(__('%s, ping error:'),$url).' '.$ping_msg);
          } else {
               # Notify ping result in database
               $cur = $this->con->openCursor($this->table);
               $cur->post_id = $post_id;
               $cur->ping_url = $url;
               $cur->ping_dt = date('Y-m-d H:i:s');
               
               $cur->insert();
          }
     }
     //@}
     
     /// @name Receive trackbacks
     //@{
     /**
     Receives a trackback and insert it as a comment of given post.
     
     @param    post_id        <b>integer</b>      Post ID
     */
     public function receive($post_id)
     {
          header('Content-Type: text/xml; charset=UTF-8');
          if (empty($_POST)) {
               http::head(405,'Method Not Allowed');
               echo
               '<?xml version="1.0" encoding="utf-8"?>'."\n".
               "<response>\n".
               "  <error>1</error>\n".
               "  <message>POST request needed</message>\n".
               "</response>";
               return;
          }
          
          $post_id = (integer) $post_id;
          
          $title = !empty($_POST['title']) ? $_POST['title'] : '';
          $excerpt = !empty($_POST['excerpt']) ? $_POST['excerpt'] : '';
          $url = !empty($_POST['url']) ? $_POST['url'] : '';
          $blog_name = !empty($_POST['blog_name']) ? $_POST['blog_name'] : '';
          $charset = '';
          $comment = '';
          
          $err = false;
          $msg = '';
          
          if ($this->core->blog === null)
          {
               $err = true;
               $msg = 'No blog.';
          }
          elseif ($url == '')
          {
               $err = true;
               $msg = 'URL parameter is required.';
          }
          elseif ($blog_name == '') {
               $err = true;
               $msg = 'Blog name is required.';
          }
          
          if (!$err)
          {
               $post = $this->core->blog->getPosts(array('post_id'=>$post_id,'post_type'=>''));
               
               if ($post->isEmpty())
               {
                    $err = true;
                    $msg = 'No such post.';
               }
               elseif (!$post->trackbacksActive())
               {
                    $err = true;
                    $msg = 'Trackbacks are not allowed for this post or weblog.';
               }
          }
          
          if (!$err)
          {
               $charset = self::getCharsetFromRequest();
               
               if (!$charset) {
                    $charset = mb_detect_encoding($title.' '.$excerpt.' '.$blog_name,
                    'UTF-8,ISO-8859-1,ISO-8859-2,ISO-8859-3,'.
                    'ISO-8859-4,ISO-8859-5,ISO-8859-6,ISO-8859-7,ISO-8859-8,'.
                    'ISO-8859-9,ISO-8859-10,ISO-8859-13,ISO-8859-14,ISO-8859-15');
               }
               
               if (strtolower($charset) != 'utf-8') {
                    $title = iconv($charset,'UTF-8',$title);
                    $excerpt = iconv($charset,'UTF-8',$excerpt);
                    $blog_name = iconv($charset,'UTF-8',$blog_name);
               }
               
               $title = trim(html::clean($title));
               $title = html::decodeEntities($title);
               $title = html::escapeHTML($title);
               $title = text::cutString($title,60);
               
               $excerpt = trim(html::clean($excerpt));
               $excerpt = html::decodeEntities($excerpt);
               $excerpt = preg_replace('/\s+/ms',' ',$excerpt);
               $excerpt = text::cutString($excerpt,252); 
               $excerpt = html::escapeHTML($excerpt).'...';
               
               $blog_name = trim(html::clean($blog_name));
               $blog_name = html::decodeEntities($blog_name);
               $blog_name = html::escapeHTML($blog_name);
               $blog_name = text::cutString($blog_name,60);
               
               $url = trim(html::clean($url));
               
               if (!$blog_name) {
                    $blog_name = 'Anonymous blog';
               }
               
               $comment =
               "<!-- TB -->\n".
               '<p><strong>'.($title ? $title : $blog_name)."</strong></p>\n".
               '<p>'.$excerpt.'</p>';
               
               $cur = $this->core->con->openCursor($this->core->prefix.'comment');
               $cur->comment_author = (string) $blog_name;
               $cur->comment_site = (string) $url;
               $cur->comment_content = (string) $comment;
               $cur->post_id = $post_id;
               $cur->comment_trackback = 1;
               $cur->comment_status = $this->core->blog->settings->system->trackbacks_pub ? 1 : -1;
               $cur->comment_ip = http::realIP();
               
               try
               {
                    # --BEHAVIOR-- publicBeforeTrackbackCreate
                    $this->core->callBehavior('publicBeforeTrackbackCreate',$cur);
                    if ($cur->post_id) {
                         $comment_id = $this->core->blog->addComment($cur);
                         
                         # --BEHAVIOR-- publicAfterTrackbackCreate
                         $this->core->callBehavior('publicAfterTrackbackCreate',$cur,$comment_id);
                    }
               }
               catch (Exception $e)
               {
                    $err = 1;
                    $msg = 'Something went wrong : '.$e->getMessage();
               }
          }
          
          
          $debug_trace =
          "  <debug>\n".
          '    <title>'.$title."</title>\n".
          '    <excerpt>'.$excerpt."</excerpt>\n".
          '    <url>'.$url."</url>\n".
          '    <blog_name>'.$blog_name."</blog_name>\n".
          '    <charset>'.$charset."</charset>\n".
          '    <comment>'.$comment."</comment>\n".
          "  </debug>\n";
          
          $resp =
          '<?xml version="1.0" encoding="utf-8"?>'."\n".
          "<response>\n".
          '  <error>'.(integer) $err."</error>\n";
          
          if ($msg) {
               $resp .= '  <message>'.$msg."</message>\n";
          }
          
          if (!empty($_POST['__debug'])) {
               $resp .= $debug_trace;
          }
          
          echo $resp."</response>";
     }
     //@}
     
     private static function initHttp($url,&$path)
     {
          $client = netHttp::initClient($url,$path);
          $client->setTimeout(5);
          $client->setUserAgent('Dotclear - http://www.dotclear.org/');
          $client->useGzip(false);
          $client->setPersistReferers(false);
          
          return $client;
     }
     
     private static function getCharsetFromRequest()
     {
          if (isset($_SERVER['CONTENT_TYPE']))
          {
               if (preg_match('|charset=([a-zA-Z0-9-]+)|',$_SERVER['CONTENT_TYPE'],$m)) {
                    return $m[1];
               }
          }
          
          return null;
     }
     
     /// @name Trackbacks auto discovery
     //@{
     /**
     Returns an array containing all discovered trackbacks URLs in
     <var>$text</var>.
     
     @param    text      <b>string</b>       Input text
     @return   <b>array</b>
     */
     public function discover($text)
     {
          $res = array();
          
          foreach ($this->getTextLinks($text) as $link)
          {
               if (($url = $this->getPingURL($link)) !== null) {
                    $res[] = $url;
               }
          }
          
          return $res;
     }
     //@}
     
     private function getTextLinks($text)
     {
          $res = array();
          
          # href attribute on "a" tags
          if (preg_match_all('/<a ([^>]+)>/ms', $text, $match, PREG_SET_ORDER))
          {
               for ($i = 0; $i<count($match); $i++)
               {
                    if (preg_match('/href="(http:\/\/[^"]+)"/ms', $match[$i][1], $matches)) {
                         $res[$matches[1]] = 1;
                    }
               }
          }
          unset($match);
          
          # cite attributes on "blockquote" and "q" tags
          if (preg_match_all('/<(blockquote|q) ([^>]+)>/ms', $text, $match, PREG_SET_ORDER))
          {
               for ($i = 0; $i<count($match); $i++)
               {
                    if (preg_match('/cite="(http:\/\/[^"]+)"/ms', $match[$i][2], $matches)) {
                         $res[$matches[1]] = 1;
                    }
               }
          }
          
          return array_keys($res);
     }
     
     private function getPingURL($url)
     {
          try
          {
               $http = self::initHttp($url,$path);
               $http->get($path);
               $page_content = $http->getContent();
          }
          catch (Exception $e)
          {
               return false;
          }
          
          $pattern_rdf =
          '/<rdf:RDF.*?>.*?'.
          '<rdf:Description\s+(.*?)\/>'.
          '.*?<\/rdf:RDF>'.
          '/msi';
          
          preg_match_all($pattern_rdf,$page_content,$rdf_all,PREG_SET_ORDER);
          
          for ($i=0; $i<count($rdf_all); $i++)
          {
               $rdf = $rdf_all[$i][1];
               
               if (preg_match('/dc:identifier="'.preg_quote($url,'/').'"/msi',$rdf)) {
                    if (preg_match('/trackback:ping="(.*?)"/msi',$rdf,$tb_link)) {
                         return $tb_link[1];
                    }
               }
          }
          
          return null;
     }
}
?>