includes/diffengine/Renderer/xhtml.php
author Dan
Fri, 05 Oct 2007 01:57:00 -0400
changeset 161 e1a22031b5bd
parent 1 fe660c52c48f
permissions -rw-r--r--
Major revamps to the template parser. Fixed a few security holes that could allow PHP to be injected in untimely places in TPL code. Improved Ux for XSS attempt in tplWikiFormat. Documented many functions. Backported much cleaner parser from 2.0 branch. Beautified a lot of code in the depths of the template class. Pretty much a small-scale Extreme Makeover.

<?php

/**
 * XHTML diff renderer.
 *
 * This class renders diffs in XHTML format.
 *
 * $Horde: framework/Text_Diff/Diff/Renderer/inline.php,v 1.16 2006/01/08 00:06:57 jan Exp $
 *
 * @author  Ciprian Popovici
 * @author  Dan Fuhry
 * @package Text_Diff
 */
class Text_Diff_Renderer_xhtml extends Text_Diff_Renderer {

    /**
     * Number of leading context "lines" to preserve.
     */
    var $_leading_context_lines = 5;

    /**
     * Number of trailing context "lines" to preserve.
     */
    var $_trailing_context_lines = 3;

    /**
     * Prefix for inserted text.
     */
    var $_ins_prefix = "<!-- Start added text -->\n<tr><td style='width: 0px;'>+</td><td class=\"diff-added\" style='width: 100%;'>";

    /**
     * Suffix for inserted text.
     */
    var $_ins_suffix = "</td></tr>\n<!-- End added text -->\n\n";

    /**
     * Prefix for deleted text.
     */
    var $_del_prefix = "<!-- Start deleted text -->\n<tr><td style='width: 0px;'>-</td><td class=\"diff-deleted\" style='width: 100%;'>";

    /**
     * Suffix for deleted text.
     */
    var $_del_suffix = "</td></tr>\n<!-- End deleted text -->\n\n";

    /**
     * Header for each change block.
     */
    var $_block_header = '';

    /**
     * What are we currently splitting on? Used to recurse to show word-level
     * changes.
     */
    var $_split_level = 'lines';
    
    function _blockHeader($xbeg, $xlen, $ybeg, $ylen)
    {
      return "<!-- Start block -->\n<tr><td colspan='2' class='diff-block'>Line $xbeg: {$this->_block_header}</td></tr>";
    }

    function _startBlock($header)
    {
        return $header;
    }

    function _lines($lines, $prefix = ' ', $encode = true)
    {
        if ($encode) {
            array_walk($lines, array(&$this, '_encode'));
        }

        if ($this->_split_level == 'words') {
            return implode('', $lines);
        } else {
            return implode("<br />", $lines) . "\n";
        }
    }

    function _added($lines)
    {
        array_walk($lines, array(&$this, '_encode'));
        $lines[0] = $this->_ins_prefix . $lines[0];
        $lines[count($lines) - 1] .= $this->_ins_suffix;
        return $this->_lines($lines, ' ', false);
    }

    function _deleted($lines, $words = false)
    {
        array_walk($lines, array(&$this, '_encode'));
        $lines[0] = $this->_del_prefix . $lines[0];
        $lines[count($lines) - 1] .= $this->_del_suffix;
        return $this->_lines($lines, ' ', false);
    }
    
    function _context($lines)
    {
        return "<!-- Start context -->\n<tr><td></td><td class=\"diff-context\">".$this->_lines($lines).'</td></tr>'."\n<!-- End context -->\n\n";
    }

    function _changed($orig, $final)
    {
        /* If we've already split on words, don't try to do so again - just display. */ 
        if ($this->_split_level == 'words') {
            $prefix = '';
            while ($orig[0] !== false && $final[0] !== false &&
                   substr($orig[0], 0, 1) == ' ' &&
                   substr($final[0], 0, 1) == ' ') {
                $prefix .= substr($orig[0], 0, 1);
                $orig[0] = substr($orig[0], 1);
                $final[0] = substr($final[0], 1);
            }
            $ret = $prefix . $this->_deleted($orig) . $this->_added($final) . "\n";
            //echo 'DEBUG:<pre>'.htmlspecialchars($ret).'</pre>';
            return $ret;
        }

        $text1 = implode("\n", $orig);
        $text2 = implode("\n", $final);

        /* Non-printing newline marker. */
        $nl = "\0";

        /* We want to split on word boundaries, but we need to
         * preserve whitespace as well. Therefore we split on words,
         * but include all blocks of whitespace in the wordlist. */
        $diff = &new Text_Diff($this->_splitOnWords($text1, $nl),
                               $this->_splitOnWords($text2, $nl));

        /* Get the diff in inline format. */
        $renderer = &new Text_Diff_Renderer_inline(array_merge($this->getParams(),
                                                               array('split_level' => 'words')));

        /* Run the diff and get the output. */
        $ret = str_replace($nl, "<br />", $renderer->render($diff));
        //echo 'DEBUG:<pre>'.htmlspecialchars($ret).'</pre>';
        return $ret . "\n";
    }

    function _splitOnWords($string, $newlineEscape = "<br />")
    {
        $words = array();
        $length = strlen($string);
        $pos = 0;

        while ($pos < $length) {
            // Eat a word with any preceding whitespace.
            $spaces = strspn(substr($string, $pos), " \n");
            $nextpos = strcspn(substr($string, $pos + $spaces), " \n");
            $words[] = str_replace("\n", $newlineEscape, substr($string, $pos, $spaces + $nextpos));
            $pos += $spaces + $nextpos;
        }

        return $words;
    }

    function _encode(&$string)
    {
        $string = htmlspecialchars($string);
    }
    
    /**
     * Renders a diff.
     *
     * @param Text_Diff $diff  A Text_Diff object.
     *
     * @return string  The formatted output.
     */
    
    function render($diff)
    {
        $xi = $yi = 1;
        $block = false;
        $context = array();

        $nlead = $this->_leading_context_lines;
        $ntrail = $this->_trailing_context_lines;

        $output = $this->_startDiff();

        $diffs = $diff->getDiff();
        foreach ($diffs as $i => $edit) {
            if (is_a($edit, 'Text_Diff_Op_copy')) {
                if (is_array($block)) {
                    $keep = $i == count($diffs) - 1 ? $ntrail : $nlead + $ntrail;
                    if (count($edit->orig) <= $keep) {
                        $block[] = $edit;
                    } else {
                        if ($ntrail) {
                            $context = array_slice($edit->orig, 0, $ntrail);
                            $block[] = &new Text_Diff_Op_copy($context);
                        }
                        $bk = $this->_block($x0, $ntrail + $xi - $x0,
                                            $y0, $ntrail + $yi - $y0,
                                            $block);
                        $output .= $bk;
                        $block = false;
                    }
                }
                $context = $edit->orig;
            } else {
                if (!is_array($block)) {
                    $context = array_slice($context, count($context) - $nlead);
                    $x0 = $xi - count($context);
                    $y0 = $yi - count($context);
                    $block = array();
                    if ($context) {
                        $block[] = &new Text_Diff_Op_copy($context);
                    }
                }
                $block[] = $edit;
            }

            if ($edit->orig) {
                $xi += count($edit->orig);
            }
            if ($edit->final) {
                $yi += count($edit->final);
            }
        }

        if (is_array($block)) {
            $bk = $this->_block($x0, $xi - $x0,
                                $y0, $yi - $y0,
                                $block);
            $output .= $bk;
        }

        $final = $output . $this->_endDiff();
        if ($final == '') $final = '<tr><td class="diff-block">No differences.</td></tr>';
        //$final = preg_replace('#('.preg_quote($this->_ins_suffix).'|'.preg_quote($this->_del_suffix).')(.+?)('.preg_quote($this->_ins_prefix).'|'.preg_quote($this->_ins_suffix).')#', '\\1<tr><td></td><td class="diff-context>\\2</td></tr>\\3', $final);
        return '<table class="diff">'.$final.'</table>'."\n\n";
    }
    
    function _block($xbeg, $xlen, $ybeg, $ylen, &$edits)
    {
        $output = $this->_startBlock($this->_blockHeader($xbeg, $xlen, $ybeg, $ylen));

        foreach ($edits as $edit) {
            switch (strtolower(get_class($edit))) {
            case 'text_diff_op_copy':
                $output .= $this->_context($edit->orig);
                break;

            case 'text_diff_op_add':
                $output .= $this->_added($edit->final);
                break;

            case 'text_diff_op_delete':
                $output .= $this->_deleted($edit->orig);
                break;

            case 'text_diff_op_change':
                $output .= $this->_changed($edit->orig, $edit->final);
                break;
            }
        }

        return $output . $this->_endBlock();
    }

}