/** * Class used internally by Diff to actually compute the diffs. * * This class uses the xdiff PECL package (http://pecl.php.net/package/xdiff) * to compute the differences between the two input arrays. * * $Horde: framework/Text_Diff/Diff/Engine/xdiff.php,v 1.6 2008/01/04 10:07:50 jan Exp $ * * Copyright 2004-2008 The Horde Project (http://www.horde.org/) * * See the enclosed file COPYING for license information (LGPL). If you did * not receive this file, see http://opensource.org/licenses/lgpl-license.php. * * @author Jon Parise * @package Text_Diff */ class Text_Diff_Engine_xdiff { /** */ function diff($from_lines, $to_lines) { array_walk($from_lines, array('Text_Diff', 'trimNewlines')); array_walk($to_lines, array('Text_Diff', 'trimNewlines')); /* Convert the two input arrays into strings for xdiff processing. */ $from_string = implode("\n", $from_lines); $to_string = implode("\n", $to_lines); /* Diff the two strings and convert the result to an array. */ $diff = xdiff_string_diff($from_string, $to_string, count($to_lines)); $diff = explode("\n", $diff); /* Walk through the diff one line at a time. We build the $edits * array of diff operations by reading the first character of the * xdiff output (which is in the "unified diff" format). * * Note that we don't have enough information to detect "changed" * lines using this approach, so we can't add Text_Diff_Op_changed * instances to the $edits array. The result is still perfectly * valid, albeit a little less descriptive and efficient. */ $edits = array(); foreach ($diff as $line) { switch ($line[0]) { case ' ': $edits[] = &new Text_Diff_Op_copy(array(substr($line, 1))); break; case '+': $edits[] = &new Text_Diff_Op_add(array(substr($line, 1))); break; case '-': $edits[] = &new Text_Diff_Op_delete(array(substr($line, 1))); break; } } return $edits; } }
