ILIAS\COPage\WordDiff\WordDiff Class Reference

Creates word-level marked-up versions of two text sequences. More...

Collaboration diagram for ILIAS\COPage\WordDiff\WordDiff:

Public Member Functions
	__construct (array $original_lines, array $closing_lines)
	orig ()
	closing ()

Private Member Functions
	split (array $lines)
	findMatches (array $left, array $right)
	findMatchesInRange (array $left, array $right, int $left_offset, int $right_offset)
	lcsLengths (array $left, array $right)
	appendChangedTokens (array $tokens, string $tag, array &$output_tokens, array &$output_tags)
	render (array $tokens, array $tags)
	flushGroup (string &$line, string &$group, string $tag)

Private Attributes
const	MAX_LINE_LENGTH = 10000
array	$original
array	$closing

Detailed Description

Creates word-level marked-up versions of two text sequences.

Definition at line 26 of file class.WordDiff.php.

Constructor & Destructor Documentation

__construct()

ILIAS\COPage\WordDiff\WordDiff::__construct	(	array	$original_lines,
		array	$closing_lines
	)

Parameters

list<string>	$original_lines
list<string>	$closing_lines

Definition at line 40 of file class.WordDiff.php.

    {
        [$original_words, $original_comparison] = $this->split($original_lines);
        [$closing_words, $closing_comparison] = $this->split($closing_lines);
 
        $matches = $this->findMatches($original_comparison, $closing_comparison);
        $original_tokens = [];
        $original_tags = [];
        $closing_tokens = [];
        $closing_tags = [];
        $original_position = 0;
        $closing_position = 0;
 
        foreach ($matches as [$original_match, $closing_match]) {
            $this->appendChangedTokens(
                array_slice($original_words, $original_position, $original_match - $original_position),
                'del',
                $original_tokens,
                $original_tags
            );
            $this->appendChangedTokens(
                array_slice($closing_words, $closing_position, $closing_match - $closing_position),
                'ins',
                $closing_tokens,
                $closing_tags
            );
 
            $original_tokens[] = $original_words[$original_match];
            $original_tags[] = '';
            $closing_tokens[] = $closing_words[$closing_match];
            $closing_tags[] = '';
            $original_position = $original_match + 1;
            $closing_position = $closing_match + 1;
        }
 
        $this->appendChangedTokens(
            array_slice($original_words, $original_position),
            'del',
            $original_tokens,
            $original_tags
        );
        $this->appendChangedTokens(
            array_slice($closing_words, $closing_position),
            'ins',
            $closing_tokens,
            $closing_tags
        );
 
        $this->original = $this->render($original_tokens, $original_tags);
        $this->closing = $this->render($closing_tokens, $closing_tags);
    }

References ILIAS\COPage\WordDiff\WordDiff\appendChangedTokens(), ILIAS\COPage\WordDiff\WordDiff\closing(), ILIAS\COPage\WordDiff\WordDiff\findMatches(), ILIAS\COPage\WordDiff\WordDiff\render(), and ILIAS\COPage\WordDiff\WordDiff\split().

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Member Function Documentation

appendChangedTokens()

ILIAS\COPage\WordDiff\WordDiff::appendChangedTokens ( array  $tokens, string  $tag, array &  $output_tokens, array &  $output_tags  )

private

Parameters

list<string>	$tokens
list<string>	$output_tokens
list<string>	$output_tags

Definition at line 231 of file class.WordDiff.php.

     : void {
        foreach ($tokens as $token) {
            $output_tokens[] = $token;
            $output_tags[] = $tag;
        }
    }

References $token.

Referenced by ILIAS\COPage\WordDiff\WordDiff\__construct().

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closing()

ILIAS\COPage\WordDiff\WordDiff::closing

(

)

Returns

list<string>

Definition at line 99 of file class.WordDiff.php.

                             : array
    {
        return $this->closing;
    }

References ILIAS\COPage\WordDiff\WordDiff\$closing.

Referenced by ILIAS\COPage\WordDiff\WordDiff\__construct().

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findMatches()

ILIAS\COPage\WordDiff\WordDiff::findMatches ( array  $left, array  $right  )

private

Parameters

list<string>	$left
list<string>	$right

Returns

list<array{int, int}>

Definition at line 144 of file class.WordDiff.php.

                                                           : array
    {
        if ($left === $right) {
            $matches = [];
            foreach ($left as $index => $_word) {
                $matches[] = [$index, $index];
            }
            return $matches;
        }
 
        return $this->findMatchesInRange($left, $right, 0, 0);
    }

References ILIAS\COPage\WordDiff\WordDiff\findMatchesInRange().

Referenced by ILIAS\COPage\WordDiff\WordDiff\__construct().

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findMatchesInRange()

ILIAS\COPage\WordDiff\WordDiff::findMatchesInRange ( array  $left, array  $right, int  $left_offset, int  $right_offset  )

private

Parameters

list<string>	$left
list<string>	$right

Returns

list<array{int, int}>

Definition at line 162 of file class.WordDiff.php.

     : array {
        if ($left === [] || $right === []) {
            return [];
        }
 
        if (count($left) === 1) {
            $position = array_search($left[0], $right, true);
            return $position === false ? [] : [[$left_offset, $right_offset + $position]];
        }
 
        $middle = intdiv(count($left), 2);
        $left_half = array_slice($left, 0, $middle);
        $right_half = array_slice($left, $middle);
        $forward_lengths = $this->lcsLengths($left_half, $right);
        $backward_lengths = $this->lcsLengths(array_reverse($right_half), array_reverse($right));
 
        $right_split = 0;
        $longest = -1;
        $right_length = count($right);
        for ($index = 0; $index <= $right_length; $index++) {
            $length = $forward_lengths[$index] + $backward_lengths[$right_length - $index];
            if ($length > $longest) {
                $longest = $length;
                $right_split = $index;
            }
        }
 
        return array_merge(
            $this->findMatchesInRange($left_half, array_slice($right, 0, $right_split), $left_offset, $right_offset),
            $this->findMatchesInRange(
                $right_half,
                array_slice($right, $right_split),
                $left_offset + $middle,
                $right_offset + $right_split
            )
        );
    }

Referenced by ILIAS\COPage\WordDiff\WordDiff\findMatches().

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flushGroup()

ILIAS\COPage\WordDiff\WordDiff::flushGroup ( string &  $line, string &  $group, string  $tag  )

private

Definition at line 276 of file class.WordDiff.php.

                                                                           : void
    {
        if ($group !== '') {
            if ($tag === 'ins') {
                $line .= '[ilDiffInsStart]' . htmlspecialchars($group) . '[ilDiffInsEnd]';
            } elseif ($tag === 'del') {
                $line .= '[ilDiffDelStart]' . htmlspecialchars($group) . '[ilDiffDelEnd]';
            } else {
                $line .= htmlspecialchars($group);
            }
        }
        $group = '';
    }

lcsLengths()

ILIAS\COPage\WordDiff\WordDiff::lcsLengths ( array  $left, array  $right  )

private

Parameters

list<string>	$left
list<string>	$right

Returns

list<int>

Definition at line 210 of file class.WordDiff.php.

                                                          : array
    {
        $previous = array_fill(0, count($right) + 1, 0);
        foreach ($left as $left_word) {
            $current = [0];
            foreach ($right as $index => $right_word) {
                $current[] = $left_word === $right_word
                    ? $previous[$index] + 1
                    : max($previous[$index + 1], $current[$index]);
            }
            $previous = $current;
        }
 
        return $previous;
    }

orig()

ILIAS\COPage\WordDiff\WordDiff::orig

(

)

Returns

list<string>

Definition at line 93 of file class.WordDiff.php.

                          : array
    {
        return $this->original;
    }

References ILIAS\COPage\WordDiff\WordDiff\$original.

render()

ILIAS\COPage\WordDiff\WordDiff::render ( array  $tokens, array  $tags  )

private

Parameters

list<string>	$tokens
list<string>	$tags

Returns

list<string>

Definition at line 248 of file class.WordDiff.php.

                                                       : array
    {
        $lines = [];
        $line = '';
        $group = '';
        $current_tag = '';
 
        foreach ($tokens as $index => $token) {
            $tag = $tags[$index];
            if ($tag !== $current_tag) {
                $this->flushGroup($line, $group, $current_tag);
                $current_tag = $tag;
            }
 
            if ($token !== '' && $token[0] === "\n") {
                $this->flushGroup($line, $group, $current_tag);
                $lines[] = $line !== '' ? $line : ' ';
                $line = '';
                $token = substr($token, 1);
            }
            $group .= $token;
        }
 
        $this->flushGroup($line, $group, $current_tag);
        $lines[] = $line !== '' ? $line : ' ';
        return $lines;
    }

References $token.

Referenced by ILIAS\COPage\WordDiff\WordDiff\__construct().

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split()

ILIAS\COPage\WordDiff\WordDiff::split ( array  $lines )

private

Parameters

list<string>

$lines

Returns

array{list<string>, list<string>}

Definition at line 108 of file class.WordDiff.php.

                                        : array
    {
        $words = [];
        $comparison = [];
 
        foreach ($lines as $index => $line) {
            if ($index > 0) {
                $words[] = "\n";
                $comparison[] = "\n";
            }
 
            if (strlen($line) > self::MAX_LINE_LENGTH) {
                $words[] = $line;
                $comparison[] = $line;
                continue;
            }
 
            $matches = [];
            if (preg_match_all(
                '/ ( [^\S\n]+ | [0-9_A-Za-z\x80-\xff]+ | . ) (?: (?!< \n) [^\S\n])? /xs',
                $line,
                $matches
            )) {
                array_push($words, ...$matches[0]);
                array_push($comparison, ...$matches[1]);
            }
        }
 
        return [$words, $comparison];
    }

Referenced by ILIAS\COPage\WordDiff\WordDiff\__construct().

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Field Documentation

$closing

array ILIAS\COPage\WordDiff\WordDiff::$closing

private

Definition at line 34 of file class.WordDiff.php.

Referenced by ILIAS\COPage\WordDiff\WordDiff\closing().

$original

array ILIAS\COPage\WordDiff\WordDiff::$original

private

Definition at line 31 of file class.WordDiff.php.

Referenced by ILIAS\COPage\WordDiff\WordDiff\orig().

MAX_LINE_LENGTH

const ILIAS\COPage\WordDiff\WordDiff::MAX_LINE_LENGTH = 10000

private

Definition at line 28 of file class.WordDiff.php.

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The documentation for this class was generated from the following file:

• components/ILIAS/COPage/WordDiff/class.WordDiff.php