includes/CategoriesRdf.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  */
  19 use Wikimedia\Purtle\RdfWriter;
  20
  21 /**
  22  * Helper class to produce RDF representation of categories.
  23  */
  24 class CategoriesRdf {
  25         /**
  26          * Prefix used for Mediawiki ontology in the dump.
  27          */
  28         const ONTOLOGY_PREFIX = 'mediawiki';
  29         /**
  30          * Base URL for Mediawiki ontology.
  31          */
  32         const ONTOLOGY_URL = 'https://www.mediawiki.org/ontology#';
  33         /**
  34          * OWL description of the ontology.
  35          */
  36         const OWL_URL = 'https://www.mediawiki.org/ontology/ontology.owl';
  37         /**
  38          * Current version of the dump format.
  39          */
  40         const FORMAT_VERSION = "1.0";
  41         /**
  42          * @var RdfWriter
  43          */
  44         private $rdfWriter;
  45
  46         public function __construct( RdfWriter $writer ) {
  47                 $this->rdfWriter = $writer;
  48         }
  49
  50         /**
  51          * Setup prefixes relevant for the dump
  52          */
  53         public function setupPrefixes() {
  54                 $this->rdfWriter->prefix( self::ONTOLOGY_PREFIX, self::ONTOLOGY_URL );
  55                 $this->rdfWriter->prefix( 'rdfs', 'http://www.w3.org/2000/01/rdf-schema#' );
  56                 $this->rdfWriter->prefix( 'owl', 'http://www.w3.org/2002/07/owl#' );
  57                 $this->rdfWriter->prefix( 'schema', 'http://schema.org/' );
  58                 $this->rdfWriter->prefix( 'cc', 'http://creativecommons.org/ns#' );
  59         }
  60
  61         /**
  62          * Write RDF data for link between categories.
  63          * @param string $fromName Child category name
  64          * @param string $toName Parent category name
  65          */
  66         public function writeCategoryLinkData( $fromName, $toName ) {
  67                 $titleFrom = Title::makeTitle( NS_CATEGORY, $fromName );
  68                 $titleTo = Title::makeTitle( NS_CATEGORY, $toName );
  69                 $this->rdfWriter->about( $this->titleToUrl( $titleFrom ) )
  70                         ->say( self::ONTOLOGY_PREFIX, 'isInCategory' )
  71                         ->is( $this->titleToUrl( $titleTo ) );
  72         }
  73
  74         /**
  75          * Write out the data for single category.
  76          * @param string $categoryName Category name
  77          */
  78         public function writeCategoryData( $categoryName ) {
  79                 $title = Title::makeTitle( NS_CATEGORY, $categoryName );
  80                 $this->rdfWriter->about( $this->titleToUrl( $title ) )
  81                         ->say( 'a' )
  82                         ->is( self::ONTOLOGY_PREFIX, 'Category' );
  83                 $titletext = $title->getText();
  84                 $this->rdfWriter->say( 'rdfs', 'label' )->value( $titletext );
  85         }
  86
  87         /**
  88          * Convert Title to link to target page.
  89          * @param Title $title
  90          * @return string
  91          */
  92         private function titleToUrl( Title $title ) {
  93                 return $title->getFullURL( '', false, PROTO_CANONICAL );
  94         }
  95 }