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                         $userName = $user->getName();
 126                         $this->pageOrString( $name, $user->getUserPage(), wfMsgExt( 'siteuser', 'parsemag', $userName, $userName ) );
 127                 }
 128         }
 129
 130         /**
 131          * Takes an arg, for future enhancement with different rights for
 132          * different pages.
 133          */
 134         protected function rights() {
 135                 global $wgRightsPage, $wgRightsUrl, $wgRightsText;
 136
 137                 if( $wgRightsPage && ( $nt = Title::newFromText( $wgRightsPage ) )
 138                         && ($nt->getArticleID() != 0)) {
 139                         $this->page('rights', $nt);
 140                 } else if( $wgRightsUrl ){
 141                         $this->url('rights', $wgRightsUrl);
 142                 } else if( $wgRightsText ){
 143                         $this->element( 'rights', $wgRightsText );
 144                 }
 145         }
 146
 147         protected function getTerms( $url ){
 148                 global $wgLicenseTerms;
 149
 150                 if( $wgLicenseTerms ){
 151                         return $wgLicenseTerms;
 152                 } else {
 153                         $known = $this->getKnownLicenses();
 154                         if( isset( $known[$url] ) ) {
 155                                 return $known[$url];
 156                         } else {
 157                                 return array();
 158                         }
 159                 }
 160         }
 161
 162         protected function getKnownLicenses() {
 163                 $ccLicenses = array('by', 'by-nd', 'by-nd-nc', 'by-nc',
 164                                                         'by-nc-sa', 'by-sa');
 165                 $ccVersions = array('1.0', '2.0');
 166                 $knownLicenses = array();
 167
 168                 foreach ($ccVersions as $version) {
 169                         foreach ($ccLicenses as $license) {
 170                                 if( $version == '2.0' && substr( $license, 0, 2) != 'by' ) {
 171                                         # 2.0 dropped the non-attribs licenses
 172                                         continue;
 173                                 }
 174                                 $lurl = "http://creativecommons.org/licenses/{$license}/{$version}/";
 175                                 $knownLicenses[$lurl] = explode('-', $license);
 176                                 $knownLicenses[$lurl][] = 're';
 177                                 $knownLicenses[$lurl][] = 'di';
 178                                 $knownLicenses[$lurl][] = 'no';
 179                                 if (!in_array('nd', $knownLicenses[$lurl])) {
 180                                         $knownLicenses[$lurl][] = 'de';
 181                                 }
 182                         }
 183                 }
 184
 185                 /* Handle the GPL and LGPL, too. */
 186
 187                 $knownLicenses['http://creativecommons.org/licenses/GPL/2.0/'] =
 188                   array('de', 're', 'di', 'no', 'sa', 'sc');
 189                 $knownLicenses['http://creativecommons.org/licenses/LGPL/2.1/'] =
 190                   array('de', 're', 'di', 'no', 'sa', 'sc');
 191                 $knownLicenses['http://www.gnu.org/copyleft/fdl.html'] =
 192                   array('de', 're', 'di', 'no', 'sa', 'sc');
 193
 194                 return $knownLicenses;
 195         }
 196 }
 197
 198 class DublinCoreRdf extends RdfMetaData {
 199
 200         public function show(){
 201                 if( $this->setup() ){
 202                         $this->prologue();
 203                         $this->basics();
 204                         $this->epilogue();
 205                 }
 206         }
 207
 208         /**
 209          * begin of the page
 210          */
 211         protected function prologue() {
 212                 global $wgOutputEncoding;
 213
 214                 $url = htmlspecialchars( $this->reallyFullUrl() );
 215                 print <<<PROLOGUE
 216 <?xml version="1.0" encoding="{$wgOutputEncoding}" ?>
 217 <!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">
 218 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
 219         xmlns:dc="http://purl.org/dc/elements/1.1/">
 220         <rdf:Description rdf:about="{$url}">
 221
 222 PROLOGUE;
 223         }
 224
 225         /**
 226          * end of the page
 227          */
 228         protected function epilogue() {
 229                 print <<<EPILOGUE
 230         </rdf:Description>
 231 </rdf:RDF>
 232 EPILOGUE;
 233         }
 234 }
 235
 236 class CreativeCommonsRdf extends RdfMetaData {
 237
 238         public function show(){
 239                 if( $this->setup() ){
 240                         global $wgRightsUrl;
 241
 242                         $url = $this->reallyFullUrl();
 243
 244                         $this->prologue();
 245                         $this->subPrologue('Work', $url);
 246
 247                         $this->basics();
 248                         if( $wgRightsUrl ){
 249                                 $url = htmlspecialchars( $wgRightsUrl );
 250                                 print "\t\t<cc:license rdf:resource=\"$url\" />\n";
 251                         }
 252
 253                         $this->subEpilogue('Work');
 254
 255                         if( $wgRightsUrl ){
 256                                 $terms = $this->getTerms( $wgRightsUrl );
 257                                 if( $terms ){
 258                                         $this->subPrologue( 'License', $wgRightsUrl );
 259                                         $this->license( $terms );
 260                                         $this->subEpilogue( 'License' );
 261                                 }
 262                         }
 263                 }
 264
 265                 $this->epilogue();
 266         }
 267
 268         protected function prologue() {
 269                 global $wgOutputEncoding;
 270                 echo <<<PROLOGUE
 271 <?xml version='1.0'  encoding="{$wgOutputEncoding}" ?>
 272 <rdf:RDF xmlns:cc="http://web.resource.org/cc/"
 273         xmlns:dc="http://purl.org/dc/elements/1.1/"
 274         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
 275
 276 PROLOGUE;
 277         }
 278
 279         protected function subPrologue( $type, $url ){
 280                 $url = htmlspecialchars( $url );
 281                 echo "\t<cc:{$type} rdf:about=\"{$url}\">\n";
 282         }
 283
 284         protected function subEpilogue($type) {
 285                 echo "\t</cc:{$type}>\n";
 286         }
 287
 288         protected function license($terms) {
 289
 290                 foreach( $terms as $term ){
 291                         switch( $term ) {
 292                          case 're':
 293                                 $this->term('permits', 'Reproduction'); break;
 294                          case 'di':
 295                                 $this->term('permits', 'Distribution'); break;
 296                          case 'de':
 297                                 $this->term('permits', 'DerivativeWorks'); break;
 298                          case 'nc':
 299                                 $this->term('prohibits', 'CommercialUse'); break;
 300                          case 'no':
 301                                 $this->term('requires', 'Notice'); break;
 302                          case 'by':
 303                                 $this->term('requires', 'Attribution'); break;
 304                          case 'sa':
 305                                 $this->term('requires', 'ShareAlike'); break;
 306                          case 'sc':
 307                                 $this->term('requires', 'SourceCode'); break;
 308                         }
 309                 }
 310         }
 311
 312         protected function term( $term, $name ){
 313                 print "\t\t<cc:{$term} rdf:resource=\"http://web.resource.org/cc/{$name}\" />\n";
 314         }
 315
 316         protected function epilogue() {
 317                 echo "</rdf:RDF>\n";
 318         }
 319 }