CaffGeek/MBACNationals

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Web.Admin/2014/wordpress/wp-includes/wp-diff.php

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1 day
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<?php
/**
 * WordPress Diff bastard child of old MediaWiki Diff Formatter.
 *
 * Basically all that remains is the table structure and some method names.
 *
 * @package WordPress
 * @subpackage Diff
 */

if ( !class_exists( 'Text_Diff' ) ) {
    /** Text_Diff class */
    require( dirname(__FILE__).'/Text/Diff.php' );
    /** Text_Diff_Renderer class */
    require( dirname(__FILE__).'/Text/Diff/Renderer.php' );
    /** Text_Diff_Renderer_inline class */
    require( dirname(__FILE__).'/Text/Diff/Renderer/inline.php' );
}

/**
 * Table renderer to display the diff lines.
 *
 * @since 2.6.0
 * @uses Text_Diff_Renderer Extends
 */
class WP_Text_Diff_Renderer_Table extends Text_Diff_Renderer {

    /**
     * @see Text_Diff_Renderer::_leading_context_lines
     * @var int
     * @access protected
     * @since 2.6.0
     */
    var $_leading_context_lines  = 10000;

    /**
     * @see Text_Diff_Renderer::_trailing_context_lines
     * @var int
     * @access protected
     * @since 2.6.0
     */
    var $_trailing_context_lines = 10000;

    /**
     * {@internal Missing Description}}
     *
     * @var float
     * @access protected
     * @since 2.6.0
     */
    var $_diff_threshold = 0.6;

    /**
     * Inline display helper object name.
     *
     * @var string
     * @access protected
     * @since 2.6.0
     */
    var $inline_diff_renderer = 'WP_Text_Diff_Renderer_inline';

    /**
     * PHP4 Constructor - Call parent constructor with params array.
     *
     * This will set class properties based on the key value pairs in the array.
     *
     * @since unknown
     *
     * @param array $params
     */
    function Text_Diff_Renderer_Table( $params = array() ) {
        $parent = get_parent_class($this);
        $this->$parent( $params );
    }

    /**
     * @ignore
     *
     * @param string $header
     * @return string
     */
    function _startBlock( $header ) {
        return '';
    }

    /**
     * @ignore
     *
     * @param array $lines
     * @param string $prefix
     */
    function _lines( $lines, $prefix=' ' ) {
    }

    /**
     * @ignore
     *
     * @param string $line HTML-escape the value.
     * @return string
     */
    function addedLine( $line ) {
        return "<td>+</td><td class='diff-addedline'>{$line}</td>";
    }

    /**
     * @ignore
     *
     * @param string $line HTML-escape the value.
     * @return string
     */
    function deletedLine( $line ) {
        return "<td>-</td><td class='diff-deletedline'>{$line}</td>";
    }

    /**
     * @ignore
     *
     * @param string $line HTML-escape the value.
     * @return string
     */
    function contextLine( $line ) {
        return "<td> </td><td class='diff-context'>{$line}</td>";
    }

    /**
     * @ignore
     *
     * @return string
     */
    function emptyLine() {
        return '<td colspan="2">&nbsp;</td>';
    }

    /**
     * @ignore
     * @access private
     *
     * @param array $lines
     * @param bool $encode
     * @return string
     */
    function _added( $lines, $encode = true ) {
        $r = '';
        foreach ($lines as $line) {
            if ( $encode )
                $line = htmlspecialchars( $line );
            $r .= '<tr>' . $this->emptyLine() . $this->addedLine( $line ) . "</tr>\n";
        }
        return $r;
    }

    /**
     * @ignore
     * @access private
     *
     * @param array $lines
     * @param bool $encode
     * @return string
     */
    function _deleted( $lines, $encode = true ) {
        $r = '';
        foreach ($lines as $line) {
            if ( $encode )
                $line = htmlspecialchars( $line );
            $r .= '<tr>' . $this->deletedLine( $line ) . $this->emptyLine() . "</tr>\n";
        }
        return $r;
    }

    /**
     * @ignore
     * @access private
     *
     * @param array $lines
     * @param bool $encode
     * @return string
     */
    function _context( $lines, $encode = true ) {
        $r = '';
        foreach ($lines as $line) {
            if ( $encode )
                $line = htmlspecialchars( $line );
            $r .= '<tr>' .
                $this->contextLine( $line ) . $this->contextLine( $line ) . "</tr>\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
     *
     * @access private
     * @since 2.6.0
     *
     * @param array $orig
     * @param array $final
     * @return string
     */
    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 <ins> or <dels>
                if ( $diff_count = preg_match_all( '!(<ins>.*?</ins>|<del>.*?</del>)!', $diff, $diff_matches ) ) {
                    // length of all text between <ins> or <del>
                    $stripped_matches = strlen(strip_tags( join(' ', $diff_matches[0]) ));
                    // since we count lengith of text between <ins> or <del> (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( '|<ins>.*?</ins>|', '', $diff );
                $final_diffs[$f] = preg_replace( '|<del>.*?</del>|', '', $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 .= '<tr>' . $this->deletedLine( $orig_line ) . $this->addedLine( $final_line ) . "</tr>\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 )
     *
     * @since 2.6.0
     *
     * @param unknown_type $orig
     * @param unknown_type $final
     * @return unknown
     */
    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.
     *
     * @since 2.6.0
     *
     * @param string $string1
     * @param string $string2
     * @return int
     */
    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);
    }

    /**
     * @ignore
     * @since 2.6.0
     *
     * @param int $a
     * @param int $b
     * @return int
     */
    function difference( $a, $b ) {
        return abs( $a - $b );
    }

}

/**
 * Better word splitting than the PEAR package provides.
 *
 * @since 2.6.0
 * @uses Text_Diff_Renderer_inline Extends
 */
class WP_Text_Diff_Renderer_inline extends Text_Diff_Renderer_inline {

    /**
     * @ignore
     * @since 2.6.0
     *
     * @param string $string
     * @param string $newlineEscape
     * @return string
     */
    function _splitOnWords($string, $newlineEscape = "\n") {
        $string = str_replace("\0", '', $string);
        $words  = preg_split( '/([^\w])/u', $string, -1, PREG_SPLIT_DELIM_CAPTURE );
        $words  = str_replace( "\n", $newlineEscape, $words );
        return $words;
    }

}

?>