build();
// $matchHtml = $diff->getDifference();
// echo $matchHtml;
class HtmlDiff {
private $content;
private $headers;
private $bodyTag;
private $bodyScripts = "";
private $bodyStyles = "";
private $oldText;
private $newText;
private $oldWords = array();
private $newWords = array();
private $wordIndices;
private $encoding;
private $specialCaseOpeningTags = array( "/]*/i", "/]*/i", "/]*/i", "/]*/i", "/]*/i", "/]*/i", "/]*/i", "/]*/i", "/]*/i", "/]*/i", '/]*/i', '/]*/i' );
private $specialCaseClosingTags = array( "", "", "", "", "", "", "", "", "", "", '', '' );
public function __construct( $oldText, $newText, $encoding = 'UTF-8' ) {
$this->oldText = $this->purifyHtml( trim( $oldText ) );
$this->newText = $this->purifyHtml( trim( $newText ) );
$this->encoding = $encoding;
$this->content = '';
}
public function getOldHtml() {
return $this->oldText;
}
public function getNewHtml() {
return $this->newText;
}
public function getDifference() {
// $this->content = $this->headers . $this->bodyTag . $this->bodyScripts . $this->bodyStyles . $this->content;
$this->content = $this->headers . $this->bodyTag . $this->content;
return $this->content;
}
private function getStringBetween( $str, $start, $end="" ) {
$expStr = preg_split( $start, $str, 2, PREG_SPLIT_DELIM_CAPTURE);
// $expStr = explode( $start, $str, 2 );
if( count( $expStr ) > 1 ) {
$this->headers = $expStr[0];
$this->bodyTag = "";
// preg_match_all('#(.*?)#is', $str, $scripts);
// preg_match_all('#(.*?)#is', $str, $styles);
if(!empty($scripts[0])) {
foreach ($scripts[0] as $skey => $svalue) {
$this->bodyScripts .= $svalue;
}
}
if(!empty($styles[0])) {
foreach ($styles[0] as $stkey => $stvalue) {
$this->bodyStyles .= $stvalue;
}
}
$sthtml = preg_replace('#(.*?)#is', '', $expStr[2]);
$sthtml = preg_replace('#(.*?)#is', '', $sthtml);
$sthtml = preg_replace('##is', '', $sthtml);
return $sthtml;
}
else
{
$this->headers = "";
return $str;
}
}
// private function purifyHtml( $html, $tags = null ) {
// if( class_exists( 'Tidy' ) ) {
// $config = array( 'output-xhtml' => true, 'indent' => false );
// $tidy = new tidy;
// $tidy->parseString( $html, $config, 'utf8' );
// $html = ( string )$tidy;
// return $this->getStringBetween( $html, '//i' );
// }
// return $html;
// }
private function purifyHtml( $html, $tags = null ) {
return $this->getStringBetween( $html, '//i' );
}
public function build() {
$this->SplitInputsToWords();
$this->IndexNewWords();
$operations = $this->Operations();
foreach( $operations as $item ) {
$this->PerformOperation( $item );
}
return $this->content;
}
private function IndexNewWords() {
$this->wordIndices = array();
foreach( $this->newWords as $i => $word ) {
if( $this->IsTag( $word ) ) {
$word = $this->StripTagAttributes( $word );
}
if( isset( $this->wordIndices[ $word ] ) ) {
$this->wordIndices[ $word ][] = $i;
} else {
$this->wordIndices[ $word ] = array( $i );
}
}
}
private function SplitInputsToWords() {
$this->oldWords = $this->ConvertHtmlToListOfWords( $this->Explode( $this->oldText ) );
$this->newWords = $this->ConvertHtmlToListOfWords( $this->Explode( $this->newText ) );
}
private function ConvertHtmlToListOfWords( $characterString ) {
$mode = 'character';
$current_word = '';
$words = array();
foreach( $characterString as $character ) {
switch ( $mode ) {
case 'character':
if( $this->IsStartOfTag( $character ) ) {
if( $current_word != '' ) {
$words[] = $current_word;
}
$current_word = "<";
$mode = 'tag';
} else if( preg_match( "[^\s]", $character ) > 0 ) {
if( $current_word != '' ) {
$words[] = $current_word;
}
$current_word = $character;
$mode = 'whitespace';
} else {
if( ctype_alnum( $character ) && ( strlen($current_word) == 0 || ctype_alnum( $current_word ) ) ) {
$current_word .= $character;
} else {
$words[] = $current_word;
$current_word = $character;
}
}
break;
case 'tag' :
if( $this->IsEndOfTag( $character ) ) {
$current_word .= ">";
$words[] = $current_word;
$current_word = "";
if( !preg_match('[^\s]', $character ) ) {
$mode = 'whitespace';
} else {
$mode = 'character';
}
} else {
$current_word .= $character;
}
break;
case 'whitespace':
if( $this->IsStartOfTag( $character ) ) {
if( $current_word != '' ) {
$words[] = $current_word;
}
$current_word = "<";
$mode = 'tag';
} else if( preg_match( "[^\s]", $character ) ) {
$current_word .= $character;
} else {
if( $current_word != '' ) {
$words[] = $current_word;
}
$current_word = $character;
$mode = 'character';
}
break;
default:
break;
}
}
if( $current_word != '' ) {
$words[] = $current_word;
}
return $words;
}
private function IsStartOfTag( $val ) {
return $val == "<";
}
private function IsEndOfTag( $val ) {
return $val == ">";
}
private function IsWhiteSpace( $value ) {
return !preg_match( '[^\s]', $value );
}
private function Explode( $value ) {
// as suggested by @onassar
return preg_split( '//', $value );
// return explode( '', $value );
}
private function PerformOperation( $operation ) {
switch( $operation->Action ) {
case 'equal' :
$this->ProcessEqualOperation( $operation, "diffdups" );
break;
// case 'delete' :
// $this->ProcessDeleteOperation( $operation, "diffdel" );
// break;
case 'insert' :
$this->ProcessInsertOperation( $operation, "diffins");
break;
case 'replace':
$this->ProcessReplaceOperation( $operation );
break;
default:
break;
}
}
private function ProcessReplaceOperation( $operation ) {
// $this->ProcessDeleteOperation( $operation, "diffmod" );
$this->ProcessInsertOperation( $operation, "diffmod" );
}
private function ProcessInsertOperation( $operation, $cssClass ) {
$text = array();
foreach( $this->newWords as $pos => $s ) {
if( $pos >= $operation->StartInNew && $pos < $operation->EndInNew ) {
$text[] = $s;
}
}
$this->InsertTag( "ins", $cssClass, $text );
}
private function ProcessDeleteOperation( $operation, $cssClass ) {
$text = array();
foreach( $this->oldWords as $pos => $s ) {
if( $pos >= $operation->StartInOld && $pos < $operation->EndInOld ) {
$text[] = $s;
}
}
$this->InsertTag( "del", $cssClass, $text );
}
// private function ProcessEqualOperation( $operation ) {
// $result = array();
// foreach( $this->newWords as $pos => $s ) {
// if( $pos >= $operation->StartInNew && $pos < $operation->EndInNew ) {
// $result[] = $s;
// }
// }
// $this->content .= implode( "", $result );
// }
private function ProcessEqualOperation( $operation, $cssClass ) {
$result = array();
foreach( $this->newWords as $pos => $s ) {
if( $pos >= $operation->StartInNew && $pos < $operation->EndInNew ) {
$result[] = $s;
}
}
$this->InsertTag( "dups", $cssClass, $result );
// $this->content .= implode( "", $result );
}
private function InsertTag( $tag, $cssClass, &$words ) {
while( true ) {
if( count( $words ) == 0 ) {
break;
}
$nonTags = $this->ExtractConsecutiveWords( $words, 'noTag' );
$specialCaseTagInjection = '';
$specialCaseTagInjectionIsBefore = false;
if( count( $nonTags ) !== 0 ) {
$text = $this->WrapText( implode( "", $nonTags ), $tag, $cssClass );
$this->content .= $text;
} else {
$firstOrDefault = false;
foreach( $this->specialCaseOpeningTags as $x ) {
if( preg_match( $x, $words[ 0 ] ) ) {
$firstOrDefault = $x;
break;
}
}
if( $firstOrDefault ) {
$specialCaseTagInjection = '';
if( $tag == "del" ) {
unset( $words[ 0 ] );
}
} else if( array_search( $words[ 0 ], $this->specialCaseClosingTags ) !== false ) {
$specialCaseTagInjection = "";
$specialCaseTagInjectionIsBefore = true;
if( $tag == "del" ) {
unset( $words[ 0 ] );
}
}
}
if( count( $words ) == 0 && count( $specialCaseTagInjection ) == 0 ) {
break;
}
if( $specialCaseTagInjectionIsBefore ) {
$this->content .= $specialCaseTagInjection . implode( "", $this->ExtractConsecutiveWords( $words, 'tag' ) );
} else {
$workTag = $this->ExtractConsecutiveWords( $words, 'tag' );
// if( isset($workTag[0]) && $this->IsOpeningTag( $workTag[ 0 ] ) && !$this->IsClosingTag( $workTag[ 0 ] ) ) {
// if(!stristr($workTag[0], "", ' class="diffmod">', $workTag[ 0 ] );
// }
// }
// }
$this->content .= implode( "", $workTag ) . $specialCaseTagInjection;
}
}
}
private function checkCondition( $word, $condition ) {
return $condition == 'tag' ? $this->IsTag( $word ) : !$this->IsTag( $word );
}
private function WrapText( $text, $tagName, $cssClass ) {
if($tagName != "script" && $tagName != "style" && $tagName != "meta" && $tagName != "link" && trim($text) != "")
{
if($cssClass == "diffdups" && trim($text) != "")
return sprintf( '<%1$s class="%2$s" style="background-color:#FE642E;" >%3$s', $tagName, $cssClass, $text );
else
return $text;
// elseif($cssClass == "diffmod")
// return sprintf( '<%1$s class="%2$s" style="text-decoration: none;" >%3$s', $tagName, $cssClass, $text );
// else
// return sprintf( '<%1$s class="%2$s" >%3$s', $tagName, $cssClass, $text );
}
}
private function ExtractConsecutiveWords( &$words, $condition ) {
$indexOfFirstTag = null;
foreach( $words as $i => $word ) {
if( !$this->checkCondition( $word, $condition ) ) {
// if(!stristr($word, " $s ) {
if( $pos >= 0 && $pos < $indexOfFirstTag ) {
$items[] = $s;
}
}
if( $indexOfFirstTag > 0 ) {
array_splice( $words, 0, $indexOfFirstTag );
}
return $items;
} else {
$items = array();
foreach( $words as $pos => $s ) {
if( $pos >= 0 && $pos <= count( $words ) ) {
$items[] = $s;
}
}
array_splice( $words, 0, count( $words ) );
return $items;
}
}
private function IsTag( $item ) {
return $this->IsOpeningTag( $item ) || $this->IsClosingTag( $item );
}
private function IsOpeningTag( $item ) {
return preg_match( "#<[^>]+>\\s*#iU", $item );
}
private function IsClosingTag( $item ) {
return preg_match( "#]+>\\s*#iU", $item );
}
private function Operations() {
$positionInOld = 0;
$positionInNew = 0;
$operations = array();
$matches = $this->MatchingBlocks();
$matches[] = new Match( count( $this->oldWords ), count( $this->newWords ), 0 );
foreach( $matches as $i => $match ) {
$matchStartsAtCurrentPositionInOld = ( $positionInOld == $match->StartInOld );
$matchStartsAtCurrentPositionInNew = ( $positionInNew == $match->StartInNew );
$action = 'none';
if( $matchStartsAtCurrentPositionInOld == false && $matchStartsAtCurrentPositionInNew == false ) {
$action = 'replace';
} else if( $matchStartsAtCurrentPositionInOld == true && $matchStartsAtCurrentPositionInNew == false ) {
$action = 'insert';
} else if( $matchStartsAtCurrentPositionInOld == false && $matchStartsAtCurrentPositionInNew == true ) {
$action = 'delete';
} else { // This occurs if the first few words are the same in both versions
$action = 'none';
}
if( $action != 'none' ) {
$operations[] = new Operation( $action, $positionInOld, $match->StartInOld, $positionInNew, $match->StartInNew );
}
if( count( $match ) !== 0 ) {
$operations[] = new Operation( 'equal', $match->StartInOld, $match->EndInOld(), $match->StartInNew, $match->EndInNew() );
}
$positionInOld = $match->EndInOld();
$positionInNew = $match->EndInNew();
}
return $operations;
}
private function MatchingBlocks() {
$matchingBlocks = array();
$this->FindMatchingBlocks( 0, count( $this->oldWords ), 0, count( $this->newWords ), $matchingBlocks );
return $matchingBlocks;
}
private function FindMatchingBlocks( $startInOld, $endInOld, $startInNew, $endInNew, &$matchingBlocks ) {
$match = $this->FindMatch( $startInOld, $endInOld, $startInNew, $endInNew );
if( $match !== null ) {
if( $startInOld < $match->StartInOld && $startInNew < $match->StartInNew ) {
$this->FindMatchingBlocks( $startInOld, $match->StartInOld, $startInNew, $match->StartInNew, $matchingBlocks );
}
$matchingBlocks[] = $match;
if( $match->EndInOld() < $endInOld && $match->EndInNew() < $endInNew ) {
$this->FindMatchingBlocks( $match->EndInOld(), $endInOld, $match->EndInNew(), $endInNew, $matchingBlocks );
}
}
}
private function StripTagAttributes( $word ) {
$word = explode( ' ', trim( $word, '<>' ) );
return '<' . $word[ 0 ] . '>';
}
private function FindMatch( $startInOld, $endInOld, $startInNew, $endInNew ) {
$bestMatchInOld = $startInOld;
$bestMatchInNew = $startInNew;
$bestMatchSize = 0;
$matchLengthAt = array();
for( $indexInOld = $startInOld; $indexInOld < $endInOld; $indexInOld++ ) {
$newMatchLengthAt = array();
$index = $this->oldWords[ $indexInOld ];
if( $this->IsTag( $index ) ) {
$index = $this->StripTagAttributes( $index );
}
if( !isset( $this->wordIndices[ $index ] ) ) {
$matchLengthAt = $newMatchLengthAt;
continue;
}
foreach( $this->wordIndices[ $index ] as $indexInNew ) {
if( $indexInNew < $startInNew ) {
continue;
}
if( $indexInNew >= $endInNew ) {
break;
}
$newMatchLength = ( isset( $matchLengthAt[ $indexInNew - 1 ] ) ? $matchLengthAt[ $indexInNew - 1 ] : 0 ) + 1;
$newMatchLengthAt[ $indexInNew ] = $newMatchLength;
if( $newMatchLength > $bestMatchSize ) {
$bestMatchInOld = $indexInOld - $newMatchLength + 1;
$bestMatchInNew = $indexInNew - $newMatchLength + 1;
$bestMatchSize = $newMatchLength;
}
}
$matchLengthAt = $newMatchLengthAt;
}
return $bestMatchSize !== 0 ? new Match( $bestMatchInOld, $bestMatchInNew, $bestMatchSize ) : null;
}
}
class Match {
public $StartInOld;
public $StartInNew;
public $Size;
public function __construct( $startInOld, $startInNew, $size ) {
$this->StartInOld = $startInOld;
$this->StartInNew = $startInNew;
$this->Size = $size;
}
public function EndInOld() {
return $this->StartInOld + $this->Size;
}
public function EndInNew() {
return $this->StartInNew + $this->Size;
}
}
class Operation {
public $Action;
public $StartInOld;
public $EndInOld;
public $StartInNew;
public $EndInNew;
public function __construct( $action, $startInOld, $endInOld, $startInNew, $endInNew ) {
$this->Action = $action;
$this->StartInOld = $startInOld;
$this->EndInOld = $endInOld;
$this->StartInNew = $startInNew;
$this->EndInNew = $endInNew;
}
}