includes/Metadata.php

   1 <?php
   2 /**
   3  * Provides DublinCore and CreativeCommons metadata
   4  *
   5  * Copyright 2004, Evan Prodromou <evan@wikitravel.org>.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  20  *
  21  * @author Evan Prodromou <evan@wikitravel.org>
  22  * @file
  23  */
  24
  25 abstract class RdfMetaData {
  26         const RDF_TYPE_PREFS = 'application/rdf+xml,text/xml;q=0.7,application/xml;q=0.5,text/rdf;q=0.1';
  27
  28         /**
  29          * Constructor
  30          * @param $article Article object
  31          */
  32         public function __construct( Article $article ) {
  33                 $this->mArticle = $article;
  34         }
  35
  36         public abstract function show();
  37
  38         /**
  39          *
  40          */
  41         protected function setup() {
  42                 global $wgOut, $wgRequest;
  43
  44                 $httpaccept = isset( $_SERVER['HTTP_ACCEPT'] ) ? $_SERVER['HTTP_ACCEPT'] : null;
  45                 $rdftype = wfNegotiateType( wfAcceptToPrefs( $httpaccept ), wfAcceptToPrefs( self::RDF_TYPE_PREFS ) );
  46
  47                 if( !$rdftype ){
  48                         wfHttpError( 406, 'Not Acceptable', wfMsg( 'notacceptable' ) );
  49                         return false;
  50                 } else {
  51                         $wgOut->disable();
  52                         $wgRequest->response()->header( "Content-type: {$rdftype}; charset=utf-8" );
  53                         $wgOut->sendCacheControl();
  54                         return true;
  55                 }
  56         }
  57
  58         /**
  59          *
  60          */
  61         protected function reallyFullUrl() {
  62                 return $this->mArticle->getTitle()->getFullURL();
  63         }
  64
  65         protected function basics() {
  66                 global $wgLanguageCode, $wgSitename;
  67
  68                 $this->element( 'title', $this->mArticle->mTitle->getText() );
  69                 $this->pageOrString( 'publisher', wfMsg( 'aboutpage' ), $wgSitename );
  70                 $this->element( 'language', $wgLanguageCode );
  71                 $this->element( 'type', 'Text' );
  72                 $this->element( 'format', 'text/html' );
  73                 $this->element( 'identifier', $this->reallyFullUrl() );
  74                 $this->element( 'date', $this->date( $this->mArticle->getTimestamp() ) );
  75
  76                 $lastEditor = User::newFromId( $this->mArticle->getUser() );
  77                 $this->person( 'creator', $lastEditor );
  78
  79                 foreach( $this->mArticle->getContributors() as $user ){
  80                         $this->person( 'contributor', $user );
  81                 }
  82
  83                 $this->rights();
  84         }
  85
  86         protected function element( $name, $value ) {
  87                 $value = htmlspecialchars( $value );
  88                 print "\t\t<dc:{$name}>{$value}</dc:{$name}>\n";
  89         }
  90
  91         protected function date($timestamp) {
  92                 return substr($timestamp, 0, 4) . '-'
  93                   . substr($timestamp, 4, 2) . '-'
  94                   . substr($timestamp, 6, 2);
  95         }
  96
  97         protected function pageOrString( $name, $page, $str ) {
  98                 if( $page instanceof Title )
  99                         $nt = $page;
 100                 else
 101                         $nt = Title::newFromText( $page );
 102
 103                 if( !$nt || $nt->getArticleID() == 0 ){
 104                         $this->element( $name, $str );
 105                 } else {
 106                         $this->page( $name, $nt );
 107                 }
 108         }
 109
 110         protected function page( $name, $title ) {
 111                 $this->url( $name, $title->getFullUrl() );
 112         }
 113
 114         protected function url($name, $url) {
 115                 $url = htmlspecialchars( $url );
 116                 print "\t\t<dc:{$name} rdf:resource=\"{$url}\" />\n";
 117         }
 118
 119         protected function person( $name, User $user ) {
 120                 if( $user->isAnon() ){
 121                         $this->element( $name, wfMsgExt( 'anonymous', array( 'parsemag' ), 1 ) );
 122                 } else {
 123                         $real = $user->getRealName();
 124                         if( $real ) {
 125                                 $this->element( $name, $real );
 126                         } else {
 127                                 $userName = $user->getName();
 128                                 $this->pageOrString( $name, $user->getUserPage(), wfMsgExt( 'siteuser', 'parsemag', $userName, $userName ) );
 129                         }
 130                 }
 131         }
 132
 133         /**
 134          * Takes an arg, for future enhancement with different rights for
 135          * different pages.
 136          */
 137         protected function rights() {
 138                 global $wgRightsPage, $wgRightsUrl, $wgRightsText;
 139
 140                 if( $wgRightsPage && ( $nt = Title::newFromText( $wgRightsPage ) )
 141                         && ($nt->getArticleID() != 0)) {
 142                         $this->page('rights', $nt);
 143                 } else if( $wgRightsUrl ){
 144                         $this->url('rights', $wgRightsUrl);
 145                 } else if( $wgRightsText ){
 146                         $this->element( 'rights', $wgRightsText );
 147                 }
 148         }
 149
 150         protected function getTerms( $url ){
 151                 global $wgLicenseTerms;
 152
 153                 if( $wgLicenseTerms ){
 154                         return $wgLicenseTerms;
 155                 } else {
 156                         $known = $this->getKnownLicenses();
 157                         if( isset( $known[$url] ) ) {
 158                                 return $known[$url];
 159                         } else {
 160                                 return array();
 161                         }
 162                 }
 163         }
 164
 165         protected function getKnownLicenses() {
 166                 $ccLicenses = array('by', 'by-nd', 'by-nd-nc', 'by-nc',
 167                                                         'by-nc-sa', 'by-sa');
 168                 $ccVersions = array('1.0', '2.0');
 169                 $knownLicenses = array();
 170
 171                 foreach ($ccVersions as $version) {
 172                         foreach ($ccLicenses as $license) {
 173                                 if( $version == '2.0' && substr( $license, 0, 2) != 'by' ) {
 174                                         # 2.0 dropped the non-attribs licenses
 175                                         continue;
 176                                 }
 177                                 $lurl = "http://creativecommons.org/licenses/{$license}/{$version}/";
 178                                 $knownLicenses[$lurl] = explode('-', $license);
 179                                 $knownLicenses[$lurl][] = 're';
 180                                 $knownLicenses[$lurl][] = 'di';
 181                                 $knownLicenses[$lurl][] = 'no';
 182                                 if (!in_array('nd', $knownLicenses[$lurl])) {
 183                                         $knownLicenses[$lurl][] = 'de';
 184                                 }
 185                         }
 186                 }
 187
 188                 /* Handle the GPL and LGPL, too. */
 189
 190                 $knownLicenses['http://creativecommons.org/licenses/GPL/2.0/'] =
 191                   array('de', 're', 'di', 'no', 'sa', 'sc');
 192                 $knownLicenses['http://creativecommons.org/licenses/LGPL/2.1/'] =
 193                   array('de', 're', 'di', 'no', 'sa', 'sc');
 194                 $knownLicenses['http://www.gnu.org/copyleft/fdl.html'] =
 195                   array('de', 're', 'di', 'no', 'sa', 'sc');
 196
 197                 return $knownLicenses;
 198         }
 199 }
 200
 201 class DublinCoreRdf extends RdfMetaData {
 202
 203         public function show(){
 204                 if( $this->setup() ){
 205                         $this->prologue();
 206                         $this->basics();
 207                         $this->epilogue();
 208                 }
 209         }
 210
 211         /**
 212          * begin of the page
 213          */
 214         protected function prologue() {
 215                 global $wgOutputEncoding;
 216
 217                 $url = htmlspecialchars( $this->reallyFullUrl() );
 218                 print <<<PROLOGUE
 219 <?xml version="1.0" encoding="{$wgOutputEncoding}" ?>
 220 <!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">
 221 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
 222         xmlns:dc="http://purl.org/dc/elements/1.1/">
 223         <rdf:Description rdf:about="{$url}">
 224
 225 PROLOGUE;
 226         }
 227
 228         /**
 229          * end of the page
 230          */
 231         protected function epilogue() {
 232                 print <<<EPILOGUE
 233         </rdf:Description>
 234 </rdf:RDF>
 235 EPILOGUE;
 236         }
 237 }
 238
 239 class CreativeCommonsRdf extends RdfMetaData {
 240
 241         public function show(){
 242                 if( $this->setup() ){
 243                         global $wgRightsUrl;
 244
 245                         $url = $this->reallyFullUrl();
 246
 247                         $this->prologue();
 248                         $this->subPrologue('Work', $url);
 249
 250                         $this->basics();
 251                         if( $wgRightsUrl ){
 252                                 $url = htmlspecialchars( $wgRightsUrl );
 253                                 print "\t\t<cc:license rdf:resource=\"$url\" />\n";
 254                         }
 255
 256                         $this->subEpilogue('Work');
 257
 258                         if( $wgRightsUrl ){
 259                                 $terms = $this->getTerms( $wgRightsUrl );
 260                                 if( $terms ){
 261                                         $this->subPrologue( 'License', $wgRightsUrl );
 262                                         $this->license( $terms );
 263                                         $this->subEpilogue( 'License' );
 264                                 }
 265                         }
 266                 }
 267
 268                 $this->epilogue();
 269         }
 270
 271         protected function prologue() {
 272                 global $wgOutputEncoding;
 273                 echo <<<PROLOGUE
 274 <?xml version='1.0'  encoding="{$wgOutputEncoding}" ?>
 275 <rdf:RDF xmlns:cc="http://web.resource.org/cc/"
 276         xmlns:dc="http://purl.org/dc/elements/1.1/"
 277         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
 278
 279 PROLOGUE;
 280         }
 281
 282         protected function subPrologue( $type, $url ){
 283                 $url = htmlspecialchars( $url );
 284                 echo "\t<cc:{$type} rdf:about=\"{$url}\">\n";
 285         }
 286
 287         protected function subEpilogue($type) {
 288                 echo "\t</cc:{$type}>\n";
 289         }
 290
 291         protected function license($terms) {
 292
 293                 foreach( $terms as $term ){
 294                         switch( $term ) {
 295                          case 're':
 296                                 $this->term('permits', 'Reproduction'); break;
 297                          case 'di':
 298                                 $this->term('permits', 'Distribution'); break;
 299                          case 'de':
 300                                 $this->term('permits', 'DerivativeWorks'); break;
 301                          case 'nc':
 302                                 $this->term('prohibits', 'CommercialUse'); break;
 303                          case 'no':
 304                                 $this->term('requires', 'Notice'); break;
 305                          case 'by':
 306                                 $this->term('requires', 'Attribution'); break;
 307                          case 'sa':
 308                                 $this->term('requires', 'ShareAlike'); break;
 309                          case 'sc':
 310                                 $this->term('requires', 'SourceCode'); break;
 311                         }
 312                 }
 313         }
 314
 315         protected function term( $term, $name ){
 316                 print "\t\t<cc:{$term} rdf:resource=\"http://web.resource.org/cc/{$name}\" />\n";
 317         }
 318
 319         protected function epilogue() {
 320                 echo "</rdf:RDF>\n";
 321         }
 322 }