$parent( $params );
}
function _startBlock( $header ) {
return '';
}
function _lines( $lines, $prefix=' ' ) {
}
// HTML-escape parameter before calling this
function addedLine( $line ) {
return "| + | {$line} | ";
}
// HTML-escape parameter before calling this
function deletedLine( $line ) {
return "- | {$line} | ";
}
// HTML-escape parameter before calling this
function contextLine( $line ) {
return " | {$line} | ";
}
function emptyLine() {
return ' | ';
}
function _added( $lines, $encode = true ) {
$r = '';
foreach ($lines as $line) {
if ( $encode )
$line = htmlspecialchars( $line );
$r .= '' . $this->emptyLine() . $this->addedLine( $line ) . "
\n";
}
return $r;
}
function _deleted( $lines, $encode = true ) {
$r = '';
foreach ($lines as $line) {
if ( $encode )
$line = htmlspecialchars( $line );
$r .= '' . $this->deletedLine( $line ) . $this->emptyLine() . "
\n";
}
return $r;
}
function _context( $lines, $encode = true ) {
$r = '';
foreach ($lines as $line) {
if ( $encode )
$line = htmlspecialchars( $line );
$r .= '' .
$this->contextLine( $line ) . $this->contextLine( $line ) . "
\n";
}
return $r;
}
// Process changed lines to do word-by-word diffs for extra highlighting (TRAC style)
// sometimes these lines can actually be deleted or added rows - we do additional processing
// to figure that out
function _changed( $orig, $final ) {
$r = '';
// Does the aforementioned additional processing
// *_matches tell what rows are "the same" in orig and final. Those pairs will be diffed to get word changes
// match is numeric: an index in other column
// match is 'X': no match. It is a new row
// *_rows are column vectors for the orig column and the final column.
// row >= 0: an indix of the $orig or $final array
// row < 0: a blank row for that column
list($orig_matches, $final_matches, $orig_rows, $final_rows) = $this->interleave_changed_lines( $orig, $final );
// These will hold the word changes as determined by an inline diff
$orig_diffs = array();
$final_diffs = array();
// Compute word diffs for each matched pair using the inline diff
foreach ( $orig_matches as $o => $f ) {
if ( is_numeric($o) && is_numeric($f) ) {
$text_diff = new Text_Diff( 'auto', array( array($orig[$o]), array($final[$f]) ) );
$renderer = new $this->inline_diff_renderer;
$diff = $renderer->render( $text_diff );
// If they're too different, don't include any or
if ( $diff_count = preg_match_all( '!(.*?|.*?)!', $diff, $diff_matches ) ) {
// length of all text between or
$stripped_matches = strlen(strip_tags( join(' ', $diff_matches[0]) ));
// since we count lengith of text between or (instead of picking just one),
// we double the length of chars not in those tags.
$stripped_diff = strlen(strip_tags( $diff )) * 2 - $stripped_matches;
$diff_ratio = $stripped_matches / $stripped_diff;
if ( $diff_ratio > $this->_diff_threshold )
continue; // Too different. Don't save diffs.
}
// Un-inline the diffs by removing del or ins
$orig_diffs[$o] = preg_replace( '|.*?|', '', $diff );
$final_diffs[$f] = preg_replace( '|.*?|', '', $diff );
}
}
foreach ( array_keys($orig_rows) as $row ) {
// Both columns have blanks. Ignore them.
if ( $orig_rows[$row] < 0 && $final_rows[$row] < 0 )
continue;
// If we have a word based diff, use it. Otherwise, use the normal line.
$orig_line = isset($orig_diffs[$orig_rows[$row]])
? $orig_diffs[$orig_rows[$row]]
: htmlspecialchars($orig[$orig_rows[$row]]);
$final_line = isset($final_diffs[$final_rows[$row]])
? $final_diffs[$final_rows[$row]]
: htmlspecialchars($final[$final_rows[$row]]);
if ( $orig_rows[$row] < 0 ) { // Orig is blank. This is really an added row.
$r .= $this->_added( array($final_line), false );
} elseif ( $final_rows[$row] < 0 ) { // Final is blank. This is really a deleted row.
$r .= $this->_deleted( array($orig_line), false );
} else { // A true changed row.
$r .= '' . $this->deletedLine( $orig_line ) . $this->addedLine( $final_line ) . "
\n";
}
}
return $r;
}
// Takes changed blocks and matches which rows in orig turned into which rows in final.
// Returns
// *_matches ( which rows match with which )
// *_rows ( order of rows in each column interleaved with blank rows as necessary )
function interleave_changed_lines( $orig, $final ) {
// Contains all pairwise string comparisons. Keys are such that this need only be a one dimensional array.
$matches = array();
foreach ( array_keys($orig) as $o ) {
foreach ( array_keys($final) as $f ) {
$matches["$o,$f"] = $this->compute_string_distance( $orig[$o], $final[$f] );
}
}
asort($matches); // Order by string distance.
$orig_matches = array();
$final_matches = array();
foreach ( $matches as $keys => $difference ) {
list($o, $f) = explode(',', $keys);
$o = (int) $o;
$f = (int) $f;
// Already have better matches for these guys
if ( isset($orig_matches[$o]) && isset($final_matches[$f]) )
continue;
// First match for these guys. Must be best match
if ( !isset($orig_matches[$o]) && !isset($final_matches[$f]) ) {
$orig_matches[$o] = $f;
$final_matches[$f] = $o;
continue;
}
// Best match of this final is already taken? Must mean this final is a new row.
if ( isset($orig_matches[$o]) )
$final_matches[$f] = 'x';
// Best match of this orig is already taken? Must mean this orig is a deleted row.
elseif ( isset($final_matches[$f]) )
$orig_matches[$o] = 'x';
}
// We read the text in this order
ksort($orig_matches);
ksort($final_matches);
// Stores rows and blanks for each column.
$orig_rows = $orig_rows_copy = array_keys($orig_matches);
$final_rows = array_keys($final_matches);
// Interleaves rows with blanks to keep matches aligned.
// We may end up with some extraneous blank rows, but we'll just ignore them later.
foreach ( $orig_rows_copy as $orig_row ) {
$final_pos = array_search($orig_matches[$orig_row], $final_rows, true);
$orig_pos = (int) array_search($orig_row, $orig_rows, true);
if ( false === $final_pos ) { // This orig is paired with a blank final.
array_splice( $final_rows, $orig_pos, 0, -1 );
} elseif ( $final_pos < $orig_pos ) { // This orig's match is up a ways. Pad final with blank rows.
$diff_pos = $final_pos - $orig_pos;
while ( $diff_pos < 0 )
array_splice( $final_rows, $orig_pos, 0, $diff_pos++ );
} elseif ( $final_pos > $orig_pos ) { // This orig's match is down a ways. Pad orig with blank rows.
$diff_pos = $orig_pos - $final_pos;
while ( $diff_pos < 0 )
array_splice( $orig_rows, $orig_pos, 0, $diff_pos++ );
}
}
// Pad the ends with blank rows if the columns aren't the same length
$diff_count = count($orig_rows) - count($final_rows);
if ( $diff_count < 0 ) {
while ( $diff_count < 0 )
array_push($orig_rows, $diff_count++);
} elseif ( $diff_count > 0 ) {
$diff_count = -1 * $diff_count;
while ( $diff_count < 0 )
array_push($final_rows, $diff_count++);
}
return array($orig_matches, $final_matches, $orig_rows, $final_rows);
/*
// Debug
echo "\n\n\n\n\n";
echo "-- DEBUG Matches: Orig -> Final --";
foreach ( $orig_matches as $o => $f ) {
echo "\n\n\n\n\n";
echo "ORIG: $o, FINAL: $f\n";
var_dump($orig[$o],$final[$f]);
}
echo "\n\n\n\n\n";
echo "-- DEBUG Matches: Final -> Orig --";
foreach ( $final_matches as $f => $o ) {
echo "\n\n\n\n\n";
echo "FINAL: $f, ORIG: $o\n";
var_dump($final[$f],$orig[$o]);
}
echo "\n\n\n\n\n";
echo "-- DEBUG Rows: Orig -- Final --";
echo "\n\n\n\n\n";
foreach ( $orig_rows as $row => $o ) {
if ( $o < 0 )
$o = 'X';
$f = $final_rows[$row];
if ( $f < 0 )
$f = 'X';
echo "$o -- $f\n";
}
echo "\n\n\n\n\n";
echo "-- END DEBUG --";
echo "\n\n\n\n\n";
return array($orig_matches, $final_matches, $orig_rows, $final_rows);
*/
}
// Computes a number that is intended to reflect the "distance" between two strings.
function compute_string_distance( $string1, $string2 ) {
// Vectors containing character frequency for all chars in each string
$chars1 = count_chars($string1);
$chars2 = count_chars($string2);
// L1-norm of difference vector.
$difference = array_sum( array_map( array(&$this, 'difference'), $chars1, $chars2 ) );
// $string1 has zero length? Odd. Give huge penalty by not dividing.
if ( !$string1 )
return $difference;
// Return distance per charcter (of string1)
return $difference / strlen($string1);
}
function difference( $a, $b ) {
return abs( $a - $b );
}
}
// Better word splitting than the PEAR package provides
class WP_Text_Diff_Renderer_inline extends Text_Diff_Renderer_inline {
function _splitOnWords($string, $newlineEscape = "\n") {
$string = str_replace("\0", '', $string);
$words = preg_split( '/([^\w])/', $string, -1, PREG_SPLIT_DELIM_CAPTURE );
$words = str_replace( "\n", $newlineEscape, $words );
return $words;
}
}
?>