[Summary view] [Print] [Text view]

   1  <?php
   2  /**
   3   * WordPress Diff bastard child of old MediaWiki Diff Formatter.
   4   *
   5   * Basically all that remains is the table structure and some method names.
   6   *
   7   * @package WordPress
   8   * @subpackage Diff
   9   */
  10  
  11  if ( !class_exists( 'Text_Diff' ) ) {
  12      /** Text_Diff class */
  13      require( dirname(__FILE__).'/Text/Diff.php' );
  14      /** Text_Diff_Renderer class */
  15      require( dirname(__FILE__).'/Text/Diff/Renderer.php' );
  16      /** Text_Diff_Renderer_inline class */
  17      require( dirname(__FILE__).'/Text/Diff/Renderer/inline.php' );
  18  }
  19  
  20  /**
  21   * Table renderer to display the diff lines.
  22   *
  23   * @since 2.6.0
  24   * @uses Text_Diff_Renderer Extends
  25   */
  26  class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {
  27  
  28      /**
  29       * @see Text_Diff_Renderer::_leading_context_lines
  30       * @var int
  31       * @access protected
  32       * @since 2.6.0
  33       */
  34      var $_leading_context_lines  = 10000;
  35  
  36      /**
  37       * @see Text_Diff_Renderer::_trailing_context_lines
  38       * @var int
  39       * @access protected
  40       * @since 2.6.0
  41       */
  42      var $_trailing_context_lines = 10000;
  43  
  44      /**
  45       * {@internal Missing Description}}
  46       *
  47       * @var float
  48       * @access protected
  49       * @since 2.6.0
  50       */
  51      var $_diff_threshold = 0.6;
  52  
  53      /**
  54       * Inline display helper object name.
  55       *
  56       * @var string
  57       * @access protected
  58       * @since 2.6.0
  59       */
  60      var $inline_diff_renderer = 'WP_Text_Diff_Renderer_inline';
  61  
  62      /**
  63       * PHP4 Constructor - Call parent constructor with params array.
  64       *
  65       * This will set class properties based on the key value pairs in the array.
  66       *
  67       * @since unknown
  68       *
  69       * @param array $params
  70       */
  71  	function Text_Diff_Renderer_Table( $params = array() ) {
  72          $parent = get_parent_class($this);
  73          $this->$parent( $params );
  74      }
  75  
  76      /**
  77       * @ignore
  78       *
  79       * @param string $header
  80       * @return string
  81       */
  82  	function _startBlock( $header ) {
  83          return '';
  84      }
  85  
  86      /**
  87       * @ignore
  88       *
  89       * @param array $lines
  90       * @param string $prefix
  91       */
  92  	function _lines( $lines, $prefix=' ' ) {
  93      }
  94  
  95      /**
  96       * @ignore
  97       *
  98       * @param string $line HTML-escape the value.
  99       * @return string
 100       */
 101  	function addedLine( $line ) {
 102          return "<td>+</td><td class='diff-addedline'>{$line}</td>";
 103      }
 104  
 105      /**
 106       * @ignore
 107       *
 108       * @param string $line HTML-escape the value.
 109       * @return string
 110       */
 111  	function deletedLine( $line ) {
 112          return "<td>-</td><td class='diff-deletedline'>{$line}</td>";
 113      }
 114  
 115      /**
 116       * @ignore
 117       *
 118       * @param string $line HTML-escape the value.
 119       * @return string
 120       */
 121  	function contextLine( $line ) {
 122          return "<td> </td><td class='diff-context'>{$line}</td>";
 123      }
 124  
 125      /**
 126       * @ignore
 127       *
 128       * @return string
 129       */
 130  	function emptyLine() {
 131          return '<td colspan="2">&nbsp;</td>';
 132      }
 133  
 134      /**
 135       * @ignore
 136       * @access private
 137       *
 138       * @param array $lines
 139       * @param bool $encode
 140       * @return string
 141       */
 142  	function _added( $lines, $encode = true ) {
 143          $r = '';
 144          foreach ($lines as $line) {
 145              if ( $encode )
 146                  $line = htmlspecialchars( $line );
 147              $r .= '<tr>' . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
 148          }
 149          return $r;
 150      }
 151  
 152      /**
 153       * @ignore
 154       * @access private
 155       *
 156       * @param array $lines
 157       * @param bool $encode
 158       * @return string
 159       */
 160  	function _deleted( $lines, $encode = true ) {
 161          $r = '';
 162          foreach ($lines as $line) {
 163              if ( $encode )
 164                  $line = htmlspecialchars( $line );
 165              $r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . "</tr>\n";
 166          }
 167          return $r;
 168      }
 169  
 170      /**
 171       * @ignore
 172       * @access private
 173       *
 174       * @param array $lines
 175       * @param bool $encode
 176       * @return string
 177       */
 178  	function _context( $lines, $encode = true ) {
 179          $r = '';
 180          foreach ($lines as $line) {
 181              if ( $encode )
 182                  $line = htmlspecialchars( $line );
 183              $r .= '<tr>' .
 184                  $this->contextLine( $line ) . $this->contextLine( $line ) . "</tr>\n";
 185          }
 186          return $r;
 187      }
 188  
 189      /**
 190       * Process changed lines to do word-by-word diffs for extra highlighting.
 191       *
 192       * (TRAC style) sometimes these lines can actually be deleted or added rows.
 193       * We do additional processing to figure that out
 194       *
 195       * @access private
 196       * @since 2.6.0
 197       *
 198       * @param array $orig
 199       * @param array $final
 200       * @return string
 201       */
 202  	function _changed( $orig, $final ) {
 203          $r = '';
 204  
 205          // Does the aforementioned additional processing
 206          // *_matches tell what rows are "the same" in orig and final.  Those pairs will be diffed to get word changes
 207          //    match is numeric: an index in other column
 208          //    match is 'X': no match.  It is a new row
 209          // *_rows are column vectors for the orig column and the final column.
 210          //    row >= 0: an indix of the $orig or $final array
 211          //    row  < 0: a blank row for that column
 212          list($orig_matches, $final_matches, $orig_rows, $final_rows) = $this->interleave_changed_lines( $orig, $final );
 213  
 214  
 215          // These will hold the word changes as determined by an inline diff
 216          $orig_diffs  = array();
 217          $final_diffs = array();
 218  
 219          // Compute word diffs for each matched pair using the inline diff
 220          foreach ( $orig_matches as $o => $f ) {
 221              if ( is_numeric($o) && is_numeric($f) ) {
 222                  $text_diff = new Text_Diff( 'auto', array( array($orig[$o]), array($final[$f]) ) );
 223                  $renderer = new $this->inline_diff_renderer;
 224                  $diff = $renderer->render( $text_diff );
 225  
 226                  // If they're too different, don't include any <ins> or <dels>
 227                  if ( $diff_count = preg_match_all( '!(<ins>.*?</ins>|<del>.*?</del>)!', $diff, $diff_matches ) ) {
 228                      // length of all text between <ins> or <del>
 229                      $stripped_matches = strlen(strip_tags( join(' ', $diff_matches[0]) ));
 230                      // since we count lengith of text between <ins> or <del> (instead of picking just one),
 231                      //    we double the length of chars not in those tags.
 232                      $stripped_diff = strlen(strip_tags( $diff )) * 2 - $stripped_matches;
 233                      $diff_ratio = $stripped_matches / $stripped_diff;
 234                      if ( $diff_ratio > $this->_diff_threshold )
 235                          continue; // Too different.  Don't save diffs.
 236                  }
 237  
 238                  // Un-inline the diffs by removing del or ins
 239                  $orig_diffs[$o]  = preg_replace( '|<ins>.*?</ins>|', '', $diff );
 240                  $final_diffs[$f] = preg_replace( '|<del>.*?</del>|', '', $diff );
 241              }
 242          }
 243  
 244          foreach ( array_keys($orig_rows) as $row ) {
 245              // Both columns have blanks.  Ignore them.
 246              if ( $orig_rows[$row] < 0 && $final_rows[$row] < 0 )
 247                  continue;
 248  
 249              // If we have a word based diff, use it.  Otherwise, use the normal line.
 250              $orig_line  = isset($orig_diffs[$orig_rows[$row]])
 251                  ? $orig_diffs[$orig_rows[$row]]
 252                  : htmlspecialchars($orig[$orig_rows[$row]]);
 253              $final_line = isset($final_diffs[$final_rows[$row]])
 254                  ? $final_diffs[$final_rows[$row]]
 255                  : htmlspecialchars($final[$final_rows[$row]]);
 256  
 257              if ( $orig_rows[$row] < 0 ) { // Orig is blank.  This is really an added row.
 258                  $r .= $this->_added( array($final_line), false );
 259              } elseif ( $final_rows[$row] < 0 ) { // Final is blank.  This is really a deleted row.
 260                  $r .= $this->_deleted( array($orig_line), false );
 261              } else { // A true changed row.
 262                  $r .= '<tr>' . $this->deletedLine( $orig_line ) . $this->addedLine( $final_line ) . "</tr>\n";
 263              }
 264          }
 265  
 266          return $r;
 267      }
 268  
 269      /**
 270       * Takes changed blocks and matches which rows in orig turned into which rows in final.
 271       *
 272       * Returns
 273       *    *_matches ( which rows match with which )
 274       *    *_rows ( order of rows in each column interleaved with blank rows as
 275       *        necessary )
 276       *
 277       * @since 2.6.0
 278       *
 279       * @param unknown_type $orig
 280       * @param unknown_type $final
 281       * @return unknown
 282       */
 283  	function interleave_changed_lines( $orig, $final ) {
 284  
 285          // Contains all pairwise string comparisons.  Keys are such that this need only be a one dimensional array.
 286          $matches = array();
 287          foreach ( array_keys($orig) as $o ) {
 288              foreach ( array_keys($final) as $f ) {
 289                  $matches["$o,$f"] = $this->compute_string_distance( $orig[$o], $final[$f] );
 290              }
 291          }
 292          asort($matches); // Order by string distance.
 293  
 294          $orig_matches  = array();
 295          $final_matches = array();
 296  
 297          foreach ( $matches as $keys => $difference ) {
 298              list($o, $f) = explode(',', $keys);
 299              $o = (int) $o;
 300              $f = (int) $f;
 301  
 302              // Already have better matches for these guys
 303              if ( isset($orig_matches[$o]) && isset($final_matches[$f]) )
 304                  continue;
 305  
 306              // First match for these guys.  Must be best match
 307              if ( !isset($orig_matches[$o]) && !isset($final_matches[$f]) ) {
 308                  $orig_matches[$o] = $f;
 309                  $final_matches[$f] = $o;
 310                  continue;
 311              }
 312  
 313              // Best match of this final is already taken?  Must mean this final is a new row.
 314              if ( isset($orig_matches[$o]) )
 315                  $final_matches[$f] = 'x';
 316  
 317              // Best match of this orig is already taken?  Must mean this orig is a deleted row.
 318              elseif ( isset($final_matches[$f]) )
 319                  $orig_matches[$o] = 'x';
 320          }
 321  
 322          // We read the text in this order
 323          ksort($orig_matches);
 324          ksort($final_matches);
 325  
 326  
 327          // Stores rows and blanks for each column.
 328          $orig_rows = $orig_rows_copy = array_keys($orig_matches);
 329          $final_rows = array_keys($final_matches);
 330  
 331          // Interleaves rows with blanks to keep matches aligned.
 332          // We may end up with some extraneous blank rows, but we'll just ignore them later.
 333          foreach ( $orig_rows_copy as $orig_row ) {
 334              $final_pos = array_search($orig_matches[$orig_row], $final_rows, true);
 335              $orig_pos = (int) array_search($orig_row, $orig_rows, true);
 336  
 337              if ( false === $final_pos ) { // This orig is paired with a blank final.
 338                  array_splice( $final_rows, $orig_pos, 0, -1 );
 339              } elseif ( $final_pos < $orig_pos ) { // This orig's match is up a ways.  Pad final with blank rows.
 340                  $diff_pos = $final_pos - $orig_pos;
 341                  while ( $diff_pos < 0 )
 342                      array_splice( $final_rows, $orig_pos, 0, $diff_pos++ );
 343              } elseif ( $final_pos > $orig_pos ) { // This orig's match is down a ways.  Pad orig with blank rows.
 344                  $diff_pos = $orig_pos - $final_pos;
 345                  while ( $diff_pos < 0 )
 346                      array_splice( $orig_rows, $orig_pos, 0, $diff_pos++ );
 347              }
 348          }
 349  
 350  
 351          // Pad the ends with blank rows if the columns aren't the same length
 352          $diff_count = count($orig_rows) - count($final_rows);
 353          if ( $diff_count < 0 ) {
 354              while ( $diff_count < 0 )
 355                  array_push($orig_rows, $diff_count++);
 356          } elseif ( $diff_count > 0 ) {
 357              $diff_count = -1 * $diff_count;
 358              while ( $diff_count < 0 )
 359                  array_push($final_rows, $diff_count++);
 360          }
 361  
 362          return array($orig_matches, $final_matches, $orig_rows, $final_rows);
 363  
 364  /*
 365          // Debug
 366          echo "\n\n\n\n\n";
 367  
 368          echo "-- DEBUG Matches: Orig -> Final --";
 369  
 370          foreach ( $orig_matches as $o => $f ) {
 371              echo "\n\n\n\n\n";
 372              echo "ORIG: $o, FINAL: $f\n";
 373              var_dump($orig[$o],$final[$f]);
 374          }
 375          echo "\n\n\n\n\n";
 376  
 377          echo "-- DEBUG Matches: Final -> Orig --";
 378  
 379          foreach ( $final_matches as $f => $o ) {
 380              echo "\n\n\n\n\n";
 381              echo "FINAL: $f, ORIG: $o\n";
 382              var_dump($final[$f],$orig[$o]);
 383          }
 384          echo "\n\n\n\n\n";
 385  
 386          echo "-- DEBUG Rows: Orig -- Final --";
 387  
 388          echo "\n\n\n\n\n";
 389          foreach ( $orig_rows as $row => $o ) {
 390              if ( $o < 0 )
 391                  $o = 'X';
 392              $f = $final_rows[$row];
 393              if ( $f < 0 )
 394                  $f = 'X';
 395              echo "$o -- $f\n";
 396          }
 397          echo "\n\n\n\n\n";
 398  
 399          echo "-- END DEBUG --";
 400  
 401          echo "\n\n\n\n\n";
 402  
 403          return array($orig_matches, $final_matches, $orig_rows, $final_rows);
 404  */
 405      }
 406  
 407      /**
 408       * Computes a number that is intended to reflect the "distance" between two strings.
 409       *
 410       * @since 2.6.0
 411       *
 412       * @param string $string1
 413       * @param string $string2
 414       * @return int
 415       */
 416  	function compute_string_distance( $string1, $string2 ) {
 417          // Vectors containing character frequency for all chars in each string
 418          $chars1 = count_chars($string1);
 419          $chars2 = count_chars($string2);
 420  
 421          // L1-norm of difference vector.
 422          $difference = array_sum( array_map( array(&$this, 'difference'), $chars1, $chars2 ) );
 423  
 424          // $string1 has zero length? Odd.  Give huge penalty by not dividing.
 425          if ( !$string1 )
 426              return $difference;
 427  
 428          // Return distance per charcter (of string1)
 429          return $difference / strlen($string1);
 430      }
 431  
 432      /**
 433       * @ignore
 434       * @since 2.6.0
 435       *
 436       * @param int $a
 437       * @param int $b
 438       * @return int
 439       */
 440  	function difference( $a, $b ) {
 441          return abs( $a - $b );
 442      }
 443  
 444  }
 445  
 446  /**
 447   * Better word splitting than the PEAR package provides.
 448   *
 449   * @since 2.6.0
 450   * @uses Text_Diff_Renderer_inline Extends
 451   */
 452  class WP_Text_Diff_Renderer_inline extends Text_Diff_Renderer_inline {
 453  
 454      /**
 455       * @ignore
 456       * @since 2.6.0
 457       *
 458       * @param string $string
 459       * @param string $newlineEscape
 460       * @return string
 461       */
 462  	function _splitOnWords($string, $newlineEscape = "\n") {
 463          $string = str_replace("\0", '', $string);
 464          $words  = preg_split( '/([^\w])/u', $string, -1, PREG_SPLIT_DELIM_CAPTURE );
 465          $words  = str_replace( "\n", $newlineEscape, $words );
 466          return $words;
 467      }
 468  
 469  }
 470  
 471  ?>