includes/Metadata.php

   1 <?php
   2 /**
   3  * Metadata.php -- provides DublinCore and CreativeCommons metadata
   4  * Copyright 2004, Evan Prodromou <evan@wikitravel.org>.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * @author Evan Prodromou <evan@wikitravel.org>
  21  */
  22
  23 abstract class RdfMetaData {
  24         const RDF_TYPE_PREFS = 'application/rdf+xml,text/xml;q=0.7,application/xml;q=0.5,text/rdf;q=0.1';
  25
  26         /**
  27          * Constructor
  28          * @param $article Article object
  29          */
  30         public function __construct( Article $article ){
  31                 $this->mArticle = $article;
  32         }
  33
  34         public abstract function show();
  35
  36         /**
  37          *
  38          */
  39         protected function setup() {
  40                 global $wgOut, $wgRequest;
  41
  42                 $httpaccept = isset( $_SERVER['HTTP_ACCEPT'] ) ? $_SERVER['HTTP_ACCEPT'] : null;
  43                 $rdftype = wfNegotiateType( wfAcceptToPrefs( $httpaccept ), wfAcceptToPrefs( self::RDF_TYPE_PREFS ) );
  44
  45                 if( !$rdftype ){
  46                         wfHttpError( 406, 'Not Acceptable', wfMsg( 'notacceptable' ) );
  47                         return false;
  48                 } else {
  49                         $wgOut->disable();
  50                         $wgRequest->response()->header( "Content-type: {$rdftype}; charset=utf-8" );
  51                         $wgOut->sendCacheControl();
  52                         return true;
  53                 }
  54         }
  55
  56         /**
  57          *
  58          */
  59         protected function reallyFullUrl() {
  60                 return $this->mArticle->getTitle()->getFullURL();
  61         }
  62
  63         protected function basics() {
  64                 global $wgContLanguageCode, $wgSitename;
  65
  66                 $this->element( 'title', $this->mArticle->mTitle->getText() );
  67                 $this->pageOrString( 'publisher', wfMsg( 'aboutpage' ), $wgSitename );
  68                 $this->element( 'language', $wgContLanguageCode );
  69                 $this->element( 'type', 'Text' );
  70                 $this->element( 'format', 'text/html' );
  71                 $this->element( 'identifier', $this->reallyFullUrl() );
  72                 $this->element( 'date', $this->date( $this->mArticle->getTimestamp() ) );
  73
  74                 $lastEditor = User::newFromId( $this->mArticle->getUser() );
  75                 $this->person( 'creator', $lastEditor );
  76
  77                 foreach( $this->mArticle->getContributors() as $user ){
  78                         $this->person( 'contributor', $user );
  79                 }
  80
  81                 $this->rights();
  82         }
  83
  84         protected function element( $name, $value ) {
  85                 $value = htmlspecialchars( $value );
  86                 print "\t\t<dc:{$name}>{$value}</dc:{$name}>\n";
  87         }
  88
  89         protected function date($timestamp) {
  90                 return substr($timestamp, 0, 4) . '-'
  91                   . substr($timestamp, 4, 2) . '-'
  92                   . substr($timestamp, 6, 2);
  93         }
  94
  95         protected function pageOrString( $name, $page, $str ){
  96                 if( $page instanceof Title )
  97                         $nt = $page;
  98                 else
  99                         $nt = Title::newFromText( $page );
 100
 101                 if( !$nt || $nt->getArticleID() == 0 ){
 102                         $this->element( $name, $str );
 103                 } else {
 104                         $this->page( $name, $nt );
 105                 }
 106         }
 107
 108         protected function page( $name, $title ){
 109                 $this->url( $name, $title->getFullUrl() );
 110         }
 111
 112         protected function url($name, $url) {
 113                 $url = htmlspecialchars( $url );
 114                 print "\t\t<dc:{$name} rdf:resource=\"{$url}\" />\n";
 115         }
 116
 117         protected function person($name, User $user ){
 118                 global $wgContLang;
 119
 120                 if( $user->isAnon() ){
 121                         $this->element( $name, wfMsgExt( 'anonymous', array( 'parsemag' ), 1 ) );
 122                 } else if( $real = $user->getRealName() ) {
 123                         $this->element( $name, $real );
 124                 } else {
 125                         $this->pageOrString( $name, $user->getUserPage(), wfMsg( 'siteuser', $user->getName() ) );
 126                 }
 127         }
 128
 129         /**
 130          * Takes an arg, for future enhancement with different rights for
 131          * different pages.
 132          */
 133         protected function rights() {
 134                 global $wgRightsPage, $wgRightsUrl, $wgRightsText;
 135
 136                 if( $wgRightsPage && ( $nt = Title::newFromText( $wgRightsPage ) )
 137                         && ($nt->getArticleID() != 0)) {
 138                         $this->page('rights', $nt);
 139                 } else if( $wgRightsUrl ){
 140                         $this->url('rights', $wgRightsUrl);
 141                 } else if( $wgRightsText ){
 142                         $this->element( 'rights', $wgRightsText );
 143                 }
 144         }
 145
 146         protected function getTerms( $url ){
 147                 global $wgLicenseTerms;
 148
 149                 if( $wgLicenseTerms ){
 150                         return $wgLicenseTerms;
 151                 } else {
 152                         $known = $this->getKnownLicenses();
 153                         if( isset( $known[$url] ) ) {
 154                                 return $known[$url];
 155                         } else {
 156                                 return array();
 157                         }
 158                 }
 159         }
 160
 161         protected function getKnownLicenses() {
 162                 $ccLicenses = array('by', 'by-nd', 'by-nd-nc', 'by-nc',
 163                                                         'by-nc-sa', 'by-sa');
 164                 $ccVersions = array('1.0', '2.0');
 165                 $knownLicenses = array();
 166
 167                 foreach ($ccVersions as $version) {
 168                         foreach ($ccLicenses as $license) {
 169                                 if( $version == '2.0' && substr( $license, 0, 2) != 'by' ) {
 170                                         # 2.0 dropped the non-attribs licenses
 171                                         continue;
 172                                 }
 173                                 $lurl = "http://creativecommons.org/licenses/{$license}/{$version}/";
 174                                 $knownLicenses[$lurl] = explode('-', $license);
 175                                 $knownLicenses[$lurl][] = 're';
 176                                 $knownLicenses[$lurl][] = 'di';
 177                                 $knownLicenses[$lurl][] = 'no';
 178                                 if (!in_array('nd', $knownLicenses[$lurl])) {
 179                                         $knownLicenses[$lurl][] = 'de';
 180                                 }
 181                         }
 182                 }
 183
 184                 /* Handle the GPL and LGPL, too. */
 185
 186                 $knownLicenses['http://creativecommons.org/licenses/GPL/2.0/'] =
 187                   array('de', 're', 'di', 'no', 'sa', 'sc');
 188                 $knownLicenses['http://creativecommons.org/licenses/LGPL/2.1/'] =
 189                   array('de', 're', 'di', 'no', 'sa', 'sc');
 190                 $knownLicenses['http://www.gnu.org/copyleft/fdl.html'] =
 191                   array('de', 're', 'di', 'no', 'sa', 'sc');
 192
 193                 return $knownLicenses;
 194         }
 195 }
 196
 197 class DublinCoreRdf extends RdfMetaData {
 198
 199         public function show(){
 200                 if( $this->setup() ){
 201                         $this->prologue();
 202                         $this->basics();
 203                         $this->epilogue();
 204                 }
 205         }
 206
 207         /**
 208          * begin of the page
 209          */
 210         protected function prologue() {
 211                 global $wgOutputEncoding;
 212
 213                 $url = htmlspecialchars( $this->reallyFullUrl() );
 214                 print <<<PROLOGUE
 215 <?xml version="1.0" encoding="{$wgOutputEncoding}" ?>
 216 <!DOCTYPE rdf:RDF PUBLIC "-//DUBLIN CORE//DCMES DTD 2002/07/31//EN" "http://dublincore.org/documents/2002/07/31/dcmes-xml/dcmes-xml-dtd.dtd">
 217 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
 218         xmlns:dc="http://purl.org/dc/elements/1.1/">
 219         <rdf:Description rdf:about="{$url}">
 220
 221 PROLOGUE;
 222         }
 223
 224         /**
 225          * end of the page
 226          */
 227         protected function epilogue() {
 228                 print <<<EPILOGUE
 229         </rdf:Description>
 230 </rdf:RDF>
 231 EPILOGUE;
 232         }
 233 }
 234
 235 class CreativeCommonsRdf extends RdfMetaData {
 236
 237         public function show(){
 238                 if( $this->setup() ){
 239                         global $wgRightsUrl;
 240
 241                         $url = $this->reallyFullUrl();
 242
 243                         $this->prologue();
 244                         $this->subPrologue('Work', $url);
 245
 246                         $this->basics();
 247                         if( $wgRightsUrl ){
 248                                 $url = htmlspecialchars( $wgRightsUrl );
 249                                 print "\t\t<cc:license rdf:resource=\"$url\" />\n";
 250                         }
 251
 252                         $this->subEpilogue('Work');
 253
 254                         if( $wgRightsUrl ){
 255                                 $terms = $this->getTerms( $wgRightsUrl );
 256                                 if( $terms ){
 257                                         $this->subPrologue( 'License', $wgRightsUrl );
 258                                         $this->license( $terms );
 259                                         $this->subEpilogue( 'License' );
 260                                 }
 261                         }
 262                 }
 263
 264                 $this->epilogue();
 265         }
 266
 267         protected function prologue() {
 268                 global $wgOutputEncoding;
 269                 echo <<<PROLOGUE
 270 <?xml version='1.0'  encoding="{$wgOutputEncoding}" ?>
 271 <rdf:RDF xmlns:cc="http://web.resource.org/cc/"
 272         xmlns:dc="http://purl.org/dc/elements/1.1/"
 273         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
 274
 275 PROLOGUE;
 276         }
 277
 278         protected function subPrologue( $type, $url ){
 279                 $url = htmlspecialchars( $url );
 280                 echo "\t<cc:{$type} rdf:about=\"{$url}\">\n";
 281         }
 282
 283         protected function subEpilogue($type) {
 284                 echo "\t</cc:{$type}>\n";
 285         }
 286
 287         protected function license($terms) {
 288
 289                 foreach( $terms as $term ){
 290                         switch( $term ) {
 291                          case 're':
 292                                 $this->term('permits', 'Reproduction'); break;
 293                          case 'di':
 294                                 $this->term('permits', 'Distribution'); break;
 295                          case 'de':
 296                                 $this->term('permits', 'DerivativeWorks'); break;
 297                          case 'nc':
 298                                 $this->term('prohibits', 'CommercialUse'); break;
 299                          case 'no':
 300                                 $this->term('requires', 'Notice'); break;
 301                          case 'by':
 302                                 $this->term('requires', 'Attribution'); break;
 303                          case 'sa':
 304                                 $this->term('requires', 'ShareAlike'); break;
 305                          case 'sc':
 306                                 $this->term('requires', 'SourceCode'); break;
 307                         }
 308                 }
 309         }
 310
 311         protected function term( $term, $name ){
 312                 print "\t\t<cc:{$term} rdf:resource=\"http://web.resource.org/cc/{$name}\" />\n";
 313         }
 314
 315         protected function epilogue() {
 316                 echo "</rdf:RDF>\n";
 317         }
 318 }