system/libraries/Trackback.php

   1 <?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2 /**
   3  * CodeIgniter
   4  *
   5  * An open source application development framework for PHP 5.1.6 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2008 - 2011, EllisLab, Inc.
  10  * @license             http://codeigniter.com/user_guide/license.html
  11  * @link                http://codeigniter.com
  12  * @since               Version 1.0
  13  * @filesource
  14  */
  15
  16 // ------------------------------------------------------------------------
  17
  18 /**
  19  * Trackback Class
  20  *
  21  * Trackback Sending/Receiving Class
  22  *
  23  * @package             CodeIgniter
  24  * @subpackage  Libraries
  25  * @category    Trackbacks
  26  * @author              ExpressionEngine Dev Team
  27  * @link                http://codeigniter.com/user_guide/libraries/trackback.html
  28  */
  29 class CI_Trackback {
  30
  31         var $time_format        = 'local';
  32         var $charset            = 'UTF-8';
  33         var $data                       = array('url' => '', 'title' => '', 'excerpt' => '', 'blog_name' => '', 'charset' => '');
  34         var $convert_ascii      = TRUE;
  35         var $response           = '';
  36         var $error_msg          = array();
  37
  38         /**
  39          * Constructor
  40          *
  41          * @access      public
  42          */
  43         public function __construct()
  44         {
  45                 log_message('debug', "Trackback Class Initialized");
  46         }
  47
  48         // --------------------------------------------------------------------
  49
  50         /**
  51          * Send Trackback
  52          *
  53          * @access      public
  54          * @param       array
  55          * @return      bool
  56          */
  57         function send($tb_data)
  58         {
  59                 if ( ! is_array($tb_data))
  60                 {
  61                         $this->set_error('The send() method must be passed an array');
  62                         return FALSE;
  63                 }
  64
  65                 // Pre-process the Trackback Data
  66                 foreach (array('url', 'title', 'excerpt', 'blog_name', 'ping_url') as $item)
  67                 {
  68                         if ( ! isset($tb_data[$item]))
  69                         {
  70                                 $this->set_error('Required item missing: '.$item);
  71                                 return FALSE;
  72                         }
  73
  74                         switch ($item)
  75                         {
  76                                 case 'ping_url' : $$item = $this->extract_urls($tb_data[$item]);
  77                                         break;
  78                                 case 'excerpt'  : $$item = $this->limit_characters($this->convert_xml(strip_tags(stripslashes($tb_data[$item]))));
  79                                         break;
  80                                 case 'url'              : $$item = str_replace('&#45;', '-', $this->convert_xml(strip_tags(stripslashes($tb_data[$item]))));
  81                                         break;
  82                                 default                 : $$item = $this->convert_xml(strip_tags(stripslashes($tb_data[$item])));
  83                                         break;
  84                         }
  85
  86                         // Convert High ASCII Characters
  87                         if ($this->convert_ascii == TRUE)
  88                         {
  89                                 if ($item == 'excerpt')
  90                                 {
  91                                         $$item = $this->convert_ascii($$item);
  92                                 }
  93                                 elseif ($item == 'title')
  94                                 {
  95                                         $$item = $this->convert_ascii($$item);
  96                                 }
  97                                 elseif ($item == 'blog_name')
  98                                 {
  99                                         $$item = $this->convert_ascii($$item);
 100                                 }
 101                         }
 102                 }
 103
 104                 // Build the Trackback data string
 105                 $charset = ( ! isset($tb_data['charset'])) ? $this->charset : $tb_data['charset'];
 106
 107                 $data = "url=".rawurlencode($url)."&title=".rawurlencode($title)."&blog_name=".rawurlencode($blog_name)."&excerpt=".rawurlencode($excerpt)."&charset=".rawurlencode($charset);
 108
 109                 // Send Trackback(s)
 110                 $return = TRUE;
 111                 if (count($ping_url) > 0)
 112                 {
 113                         foreach ($ping_url as $url)
 114                         {
 115                                 if ($this->process($url, $data) == FALSE)
 116                                 {
 117                                         $return = FALSE;
 118                                 }
 119                         }
 120                 }
 121
 122                 return $return;
 123         }
 124
 125         // --------------------------------------------------------------------
 126
 127         /**
 128          * Receive Trackback  Data
 129          *
 130          * This function simply validates the incoming TB data.
 131          * It returns FALSE on failure and TRUE on success.
 132          * If the data is valid it is set to the $this->data array
 133          * so that it can be inserted into a database.
 134          *
 135          * @access      public
 136          * @return      bool
 137          */
 138         function receive()
 139         {
 140                 foreach (array('url', 'title', 'blog_name', 'excerpt') as $val)
 141                 {
 142                         if ( ! isset($_POST[$val]) OR $_POST[$val] == '')
 143                         {
 144                                 $this->set_error('The following required POST variable is missing: '.$val);
 145                                 return FALSE;
 146                         }
 147
 148                         $this->data['charset'] = ( ! isset($_POST['charset'])) ? 'auto' : strtoupper(trim($_POST['charset']));
 149
 150                         if ($val != 'url' && function_exists('mb_convert_encoding'))
 151                         {
 152                                 $_POST[$val] = mb_convert_encoding($_POST[$val], $this->charset, $this->data['charset']);
 153                         }
 154
 155                         $_POST[$val] = ($val != 'url') ? $this->convert_xml(strip_tags($_POST[$val])) : strip_tags($_POST[$val]);
 156
 157                         if ($val == 'excerpt')
 158                         {
 159                                 $_POST['excerpt'] = $this->limit_characters($_POST['excerpt']);
 160                         }
 161
 162                         $this->data[$val] = $_POST[$val];
 163                 }
 164
 165                 return TRUE;
 166         }
 167
 168         // --------------------------------------------------------------------
 169
 170         /**
 171          * Send Trackback Error Message
 172          *
 173          * Allows custom errors to be set.  By default it
 174          * sends the "incomplete information" error, as that's
 175          * the most common one.
 176          *
 177          * @access      public
 178          * @param       string
 179          * @return      void
 180          */
 181         function send_error($message = 'Incomplete Information')
 182         {
 183                 echo "<?xml version=\"1.0\" encoding=\"utf-8\"?".">\n<response>\n<error>1</error>\n<message>".$message."</message>\n</response>";
 184                 exit;
 185         }
 186
 187         // --------------------------------------------------------------------
 188
 189         /**
 190          * Send Trackback Success Message
 191          *
 192          * This should be called when a trackback has been
 193          * successfully received and inserted.
 194          *
 195          * @access      public
 196          * @return      void
 197          */
 198         function send_success()
 199         {
 200                 echo "<?xml version=\"1.0\" encoding=\"utf-8\"?".">\n<response>\n<error>0</error>\n</response>";
 201                 exit;
 202         }
 203
 204         // --------------------------------------------------------------------
 205
 206         /**
 207          * Fetch a particular item
 208          *
 209          * @access      public
 210          * @param       string
 211          * @return      string
 212          */
 213         function data($item)
 214         {
 215                 return ( ! isset($this->data[$item])) ? '' : $this->data[$item];
 216         }
 217
 218         // --------------------------------------------------------------------
 219
 220         /**
 221          * Process Trackback
 222          *
 223          * Opens a socket connection and passes the data to
 224          * the server.  Returns TRUE on success, FALSE on failure
 225          *
 226          * @access      public
 227          * @param       string
 228          * @param       string
 229          * @return      bool
 230          */
 231         function process($url, $data)
 232         {
 233                 $target = parse_url($url);
 234
 235                 // Open the socket
 236                 if ( ! $fp = @fsockopen($target['host'], 80))
 237                 {
 238                         $this->set_error('Invalid Connection: '.$url);
 239                         return FALSE;
 240                 }
 241
 242                 // Build the path
 243                 $ppath = ( ! isset($target['path'])) ? $url : $target['path'];
 244
 245                 $path = (isset($target['query']) && $target['query'] != "") ? $ppath.'?'.$target['query'] : $ppath;
 246
 247                 // Add the Trackback ID to the data string
 248                 if ($id = $this->get_id($url))
 249                 {
 250                         $data = "tb_id=".$id."&".$data;
 251                 }
 252
 253                 // Transfer the data
 254                 fputs ($fp, "POST " . $path . " HTTP/1.0\r\n" );
 255                 fputs ($fp, "Host: " . $target['host'] . "\r\n" );
 256                 fputs ($fp, "Content-type: application/x-www-form-urlencoded\r\n" );
 257                 fputs ($fp, "Content-length: " . strlen($data) . "\r\n" );
 258                 fputs ($fp, "Connection: close\r\n\r\n" );
 259                 fputs ($fp, $data);
 260
 261                 // Was it successful?
 262                 $this->response = "";
 263
 264                 while ( ! feof($fp))
 265                 {
 266                         $this->response .= fgets($fp, 128);
 267                 }
 268                 @fclose($fp);
 269
 270
 271                 if (stristr($this->response, '<error>0</error>') === FALSE)
 272                 {
 273                         $message = 'An unknown error was encountered';
 274
 275                         if (preg_match("/<message>(.*?)<\/message>/is", $this->response, $match))
 276                         {
 277                                 $message = trim($match['1']);
 278                         }
 279
 280                         $this->set_error($message);
 281                         return FALSE;
 282                 }
 283
 284                 return TRUE;
 285         }
 286
 287         // --------------------------------------------------------------------
 288
 289         /**
 290          * Extract Trackback URLs
 291          *
 292          * This function lets multiple trackbacks be sent.
 293          * It takes a string of URLs (separated by comma or
 294          * space) and puts each URL into an array
 295          *
 296          * @access      public
 297          * @param       string
 298          * @return      string
 299          */
 300         function extract_urls($urls)
 301         {
 302                 // Remove the pesky white space and replace with a comma.
 303                 $urls = preg_replace("/\s*(\S+)\s*/", "\\1,", $urls);
 304
 305                 // If they use commas get rid of the doubles.
 306                 $urls = str_replace(",,", ",", $urls);
 307
 308                 // Remove any comma that might be at the end
 309                 if (substr($urls, -1) == ",")
 310                 {
 311                         $urls = substr($urls, 0, -1);
 312                 }
 313
 314                 // Break into an array via commas
 315                 $urls = preg_split('/[,]/', $urls);
 316
 317                 // Removes duplicates
 318                 $urls = array_unique($urls);
 319
 320                 array_walk($urls, array($this, 'validate_url'));
 321
 322                 return $urls;
 323         }
 324
 325         // --------------------------------------------------------------------
 326
 327         /**
 328          * Validate URL
 329          *
 330          * Simply adds "http://" if missing
 331          *
 332          * @access      public
 333          * @param       string
 334          * @return      string
 335          */
 336         function validate_url($url)
 337         {
 338                 $url = trim($url);
 339
 340                 if (substr($url, 0, 4) != "http")
 341                 {
 342                         $url = "http://".$url;
 343                 }
 344         }
 345
 346         // --------------------------------------------------------------------
 347
 348         /**
 349          * Find the Trackback URL's ID
 350          *
 351          * @access      public
 352          * @param       string
 353          * @return      string
 354          */
 355         function get_id($url)
 356         {
 357                 $tb_id = "";
 358
 359                 if (strpos($url, '?') !== FALSE)
 360                 {
 361                         $tb_array = explode('/', $url);
 362                         $tb_end   = $tb_array[count($tb_array)-1];
 363
 364                         if ( ! is_numeric($tb_end))
 365                         {
 366                                 $tb_end  = $tb_array[count($tb_array)-2];
 367                         }
 368
 369                         $tb_array = explode('=', $tb_end);
 370                         $tb_id  = $tb_array[count($tb_array)-1];
 371                 }
 372                 else
 373                 {
 374                         $url = rtrim($url, '/');
 375
 376                         $tb_array = explode('/', $url);
 377                         $tb_id  = $tb_array[count($tb_array)-1];
 378
 379                         if ( ! is_numeric($tb_id))
 380                         {
 381                                 $tb_id  = $tb_array[count($tb_array)-2];
 382                         }
 383                 }
 384
 385                 if ( ! preg_match ("/^([0-9]+)$/", $tb_id))
 386                 {
 387                         return FALSE;
 388                 }
 389                 else
 390                 {
 391                         return $tb_id;
 392                 }
 393         }
 394
 395         // --------------------------------------------------------------------
 396
 397         /**
 398          * Convert Reserved XML characters to Entities
 399          *
 400          * @access      public
 401          * @param       string
 402          * @return      string
 403          */
 404         function convert_xml($str)
 405         {
 406                 $temp = '__TEMP_AMPERSANDS__';
 407
 408                 $str = preg_replace("/&#(\d+);/", "$temp\\1;", $str);
 409                 $str = preg_replace("/&(\w+);/",  "$temp\\1;", $str);
 410
 411                 $str = str_replace(array("&","<",">","\"", "'", "-"),
 412                                                         array("&amp;", "&lt;", "&gt;", "&quot;", "&#39;", "&#45;"),
 413                                                         $str);
 414
 415                 $str = preg_replace("/$temp(\d+);/","&#\\1;",$str);
 416                 $str = preg_replace("/$temp(\w+);/","&\\1;", $str);
 417
 418                 return $str;
 419         }
 420
 421         // --------------------------------------------------------------------
 422
 423         /**
 424          * Character limiter
 425          *
 426          * Limits the string based on the character count. Will preserve complete words.
 427          *
 428          * @access      public
 429          * @param       string
 430          * @param       integer
 431          * @param       string
 432          * @return      string
 433          */
 434         function limit_characters($str, $n = 500, $end_char = '&#8230;')
 435         {
 436                 if (strlen($str) < $n)
 437                 {
 438                         return $str;
 439                 }
 440
 441                 $str = preg_replace("/\s+/", ' ', str_replace(array("\r\n", "\r", "\n"), ' ', $str));
 442
 443                 if (strlen($str) <= $n)
 444                 {
 445                         return $str;
 446                 }
 447
 448                 $out = "";
 449                 foreach (explode(' ', trim($str)) as $val)
 450                 {
 451                         $out .= $val.' ';
 452                         if (strlen($out) >= $n)
 453                         {
 454                                 return trim($out).$end_char;
 455                         }
 456                 }
 457         }
 458
 459         // --------------------------------------------------------------------
 460
 461         /**
 462          * High ASCII to Entities
 463          *
 464          * Converts Hight ascii text and MS Word special chars
 465          * to character entities
 466          *
 467          * @access      public
 468          * @param       string
 469          * @return      string
 470          */
 471         function convert_ascii($str)
 472         {
 473                 $count  = 1;
 474                 $out    = '';
 475                 $temp   = array();
 476
 477                 for ($i = 0, $s = strlen($str); $i < $s; $i++)
 478                 {
 479                         $ordinal = ord($str[$i]);
 480
 481                         if ($ordinal < 128)
 482                         {
 483                                 $out .= $str[$i];
 484                         }
 485                         else
 486                         {
 487                                 if (count($temp) == 0)
 488                                 {
 489                                         $count = ($ordinal < 224) ? 2 : 3;
 490                                 }
 491
 492                                 $temp[] = $ordinal;
 493
 494                                 if (count($temp) == $count)
 495                                 {
 496                                         $number = ($count == 3) ? (($temp['0'] % 16) * 4096) + (($temp['1'] % 64) * 64) + ($temp['2'] % 64) : (($temp['0'] % 32) * 64) + ($temp['1'] % 64);
 497
 498                                         $out .= '&#'.$number.';';
 499                                         $count = 1;
 500                                         $temp = array();
 501                                 }
 502                         }
 503                 }
 504
 505                 return $out;
 506         }
 507
 508         // --------------------------------------------------------------------
 509
 510         /**
 511          * Set error message
 512          *
 513          * @access      public
 514          * @param       string
 515          * @return      void
 516          */
 517         function set_error($msg)
 518         {
 519                 log_message('error', $msg);
 520                 $this->error_msg[] = $msg;
 521         }
 522
 523         // --------------------------------------------------------------------
 524
 525         /**
 526          * Show error messages
 527          *
 528          * @access      public
 529          * @param       string
 530          * @param       string
 531          * @return      string
 532          */
 533         function display_errors($open = '<p>', $close = '</p>')
 534         {
 535                 $str = '';
 536                 foreach ($this->error_msg as $val)
 537                 {
 538                         $str .= $open.$val.$close;
 539                 }
 540
 541                 return $str;
 542         }
 543
 544 }
 545 // END Trackback Class
 546
 547 /* End of file Trackback.php */
 548 /* Location: ./system/libraries/Trackback.php */