includes/diff/DifferenceEngineSlotDiffRenderer.php

   1 <?php
   2 /**
   3  * Adapter for turning a DifferenceEngine into a SlotDiffRenderer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup DifferenceEngine
  22  */
  23
  24 /**
  25  * B/C adapter for turning a DifferenceEngine into a SlotDiffRenderer.
  26  * Before SlotDiffRenderer was introduced, getDiff() functionality was provided by DifferenceEngine
  27  * subclasses. Convert such a subclass into a SlotDiffRenderer.
  28  * @deprecated
  29  * @ingroup DifferenceEngine
  30  */
  31 class DifferenceEngineSlotDiffRenderer extends SlotDiffRenderer {
  32
  33         /** @var DifferenceEngine */
  34         private $differenceEngine;
  35
  36         public function __construct( DifferenceEngine $differenceEngine ) {
  37                 $this->differenceEngine = clone $differenceEngine;
  38
  39                 // Set state to loaded. This should not matter to any of the methods invoked by
  40                 // the adapter, but just in case a load does get triggered somehow, make sure it's a no-op.
  41                 $fakeContent = ContentHandler::getForModelID( CONTENT_MODEL_WIKITEXT )->makeEmptyContent();
  42                 $this->differenceEngine->setContent( $fakeContent, $fakeContent );
  43
  44                 $this->differenceEngine->markAsSlotDiffRenderer();
  45         }
  46
  47         /** @inheritDoc */
  48         public function getDiff( Content $oldContent = null, Content $newContent = null ) {
  49                 if ( !$oldContent && !$newContent ) {
  50                         throw new InvalidArgumentException( '$oldContent and $newContent cannot both be null' );
  51                 }
  52                 if ( !$oldContent || !$newContent ) {
  53                         $someContent = $newContent ?: $oldContent;
  54                         $emptyContent = $someContent->getContentHandler()->makeEmptyContent();
  55                         $oldContent = $oldContent ?: $emptyContent;
  56                         $newContent = $newContent ?: $emptyContent;
  57                 }
  58                 return $this->differenceEngine->generateContentDiffBody( $oldContent, $newContent );
  59         }
  60
  61         public function addModules( OutputPage $output ) {
  62                 $oldContext = null;
  63                 if ( $output !== $this->differenceEngine->getOutput() ) {
  64                         $oldContext = $this->differenceEngine->getContext();
  65                         $newContext = new DerivativeContext( $oldContext );
  66                         $newContext->setOutput( $output );
  67                         $this->differenceEngine->setContext( $newContext );
  68                 }
  69                 $this->differenceEngine->showDiffStyle();
  70                 if ( $oldContext ) {
  71                         $this->differenceEngine->setContext( $oldContext );
  72                 }
  73         }
  74
  75         public function getExtraCacheKeys() {
  76                 return $this->differenceEngine->getExtraCacheKeys();
  77         }
  78
  79 }