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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  * @author Evan Prodromou <evan@wikitravel.org>
  21  */
  22
  23 /**
  24  *
  25  */
  26 define('RDF_TYPE_PREFS', "application/rdf+xml,text/xml;q=0.7,application/xml;q=0.5,text/rdf;q=0.1");
  27
  28 function wfDublinCoreRdf($article) {
  29
  30         $url = dcReallyFullUrl($article->mTitle);
  31
  32         if (rdfSetup()) {
  33                 dcPrologue($url);
  34                 dcBasics($article);
  35                 dcEpilogue();
  36         }
  37 }
  38
  39 function wfCreativeCommonsRdf($article) {
  40
  41         if (rdfSetup()) {
  42                 global $wgRightsUrl;
  43
  44                 $url = dcReallyFullUrl($article->mTitle);
  45
  46                 ccPrologue();
  47                 ccSubPrologue('Work', $url);
  48                 dcBasics($article);
  49                 if (isset($wgRightsUrl)) {
  50                         $url = htmlspecialchars( $wgRightsUrl );
  51                         print "    <cc:license rdf:resource=\"$url\" />\n";
  52                 }
  53
  54                 ccSubEpilogue('Work');
  55
  56                 if (isset($wgRightsUrl)) {
  57                         $terms = ccGetTerms($wgRightsUrl);
  58                         if ($terms) {
  59                                 ccSubPrologue('License', $wgRightsUrl);
  60                                 ccLicense($terms);
  61                                 ccSubEpilogue('License');
  62                         }
  63                 }
  64         }
  65
  66         ccEpilogue();
  67 }
  68
  69 /**
  70  * @private
  71  */
  72 function rdfSetup() {
  73         global $wgOut, $wgRdfMimeType, $_SERVER;
  74
  75         $rdftype = wfNegotiateType(wfAcceptToPrefs($_SERVER['HTTP_ACCEPT']), wfAcceptToPrefs(RDF_TYPE_PREFS));
  76
  77         if (!$rdftype) {
  78                 wfHttpError(406, "Not Acceptable", wfMsg("notacceptable"));
  79                 return false;
  80         } else {
  81                 $wgOut->disable();
  82                 header( "Content-type: {$rdftype}" );
  83                 $wgOut->sendCacheControl();
  84                 return true;
  85         }
  86 }
  87
  88 /**
  89  * @private
  90  */
  91 function dcPrologue($url) {
  92         global $wgOutputEncoding;
  93
  94         $url = htmlspecialchars( $url );
  95         print "<" . "?xml version=\"1.0\" encoding=\"{$wgOutputEncoding}\" ?" . ">
  96
  97 <!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\">
  98
  99 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
 100          xmlns:dc=\"http://purl.org/dc/elements/1.1/\">
 101   <rdf:Description rdf:about=\"$url\">
 102 ";
 103 }
 104
 105 /**
 106  * @private
 107  */
 108 function dcEpilogue() {
 109         print "
 110   </rdf:Description>
 111 </rdf:RDF>
 112 ";
 113 }
 114
 115 /**
 116  * @private
 117  */
 118 function dcBasics($article) {
 119         global $wgLanguageCode, $wgSitename;
 120
 121         dcElement('title', $article->mTitle->getText());
 122         dcPageOrString('publisher', wfMsg('aboutpage'), $wgSitename);
 123         dcElement('language', $wgLanguageCode);
 124         dcElement('type', 'Text');
 125         dcElement('format', 'text/html');
 126         dcElement('identifier', dcReallyFullUrl($article->mTitle));
 127         dcElement('date', dcDate($article->getTimestamp()));
 128
 129         $last_editor = $article->getUser();
 130
 131         if ($last_editor == 0) {
 132                 dcPerson('creator', 0);
 133         } else {
 134                 dcPerson('creator', $last_editor, $article->getUserText(),
 135                         User::whoIsReal($last_editor));
 136         }
 137
 138         $contributors = $article->getContributors();
 139
 140         foreach ($contributors as $user_parts) {
 141                 dcPerson('contributor', $user_parts[0], $user_parts[1], $user_parts[2]);
 142         }
 143
 144         dcRights($article);
 145 }
 146
 147 /**
 148  * @private
 149  */
 150 function ccPrologue() {
 151         global $wgOutputEncoding;
 152
 153         echo "<" . "?xml version='1.0'  encoding='{$wgOutputEncoding}' ?" . ">
 154
 155 <rdf:RDF xmlns:cc=\"http://web.resource.org/cc/\"
 156          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
 157          xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">
 158 ";
 159 }
 160
 161 /**
 162  * @private
 163  */
 164 function ccSubPrologue($type, $url) {
 165         $url = htmlspecialchars( $url );
 166         echo "  <cc:{$type} rdf:about=\"{$url}\">\n";
 167 }
 168
 169 /**
 170  * @private
 171  */
 172 function ccSubEpilogue($type) {
 173         echo "  </cc:{$type}>\n";
 174 }
 175
 176 /**
 177  * @private
 178  */
 179 function ccLicense($terms) {
 180
 181         foreach ($terms as $term) {
 182                 switch ($term) {
 183                 case 're':
 184                         ccTerm('permits', 'Reproduction'); break;
 185                 case 'di':
 186                         ccTerm('permits', 'Distribution'); break;
 187                 case 'de':
 188                         ccTerm('permits', 'DerivativeWorks'); break;
 189                 case 'nc':
 190                         ccTerm('prohibits', 'CommercialUse'); break;
 191                 case 'no':
 192                         ccTerm('requires', 'Notice'); break;
 193                 case 'by':
 194                         ccTerm('requires', 'Attribution'); break;
 195                 case 'sa':
 196                         ccTerm('requires', 'ShareAlike'); break;
 197                 case 'sc':
 198                         ccTerm('requires', 'SourceCode'); break;
 199                 }
 200         }
 201 }
 202
 203 /**
 204  * @private
 205  */
 206 function ccTerm($term, $name) {
 207         print "    <cc:{$term} rdf:resource=\"http://web.resource.org/cc/{$name}\" />\n";
 208 }
 209
 210 /**
 211  * @private
 212  */
 213 function ccEpilogue() {
 214         echo "</rdf:RDF>\n";
 215 }
 216
 217 /**
 218  * @private
 219  */
 220 function dcElement($name, $value) {
 221         $value = htmlspecialchars( $value );
 222         print "    <dc:{$name}>{$value}</dc:{$name}>\n";
 223 }
 224
 225 /**
 226  * @private
 227  */
 228 function dcDate($timestamp) {
 229         return substr($timestamp, 0, 4) . '-'
 230                 . substr($timestamp, 4, 2) . '-'
 231                 . substr($timestamp, 6, 2);
 232 }
 233
 234 /**
 235  * @private
 236  */
 237 function dcReallyFullUrl($title) {
 238         return $title->getFullURL();
 239 }
 240
 241 /**
 242  * @private
 243  */
 244 function dcPageOrString($name, $page, $str) {
 245         $nt = Title::newFromText($page);
 246
 247         if (!$nt || $nt->getArticleID() == 0) {
 248                 dcElement($name, $str);
 249         } else {
 250                 dcPage($name, $nt);
 251         }
 252 }
 253
 254 /**
 255  * @private
 256  */
 257 function dcPage($name, $title) {
 258         dcUrl($name, dcReallyFullUrl($title));
 259 }
 260
 261 /**
 262  * @private
 263  */
 264 function dcUrl($name, $url) {
 265         $url = htmlspecialchars( $url );
 266         print "    <dc:{$name} rdf:resource=\"{$url}\" />\n";
 267 }
 268
 269 /**
 270  * @private
 271  */
 272 function dcPerson($name, $id, $user_name='', $user_real_name='') {
 273         global $wgLang;
 274
 275         if ($id == 0) {
 276                 dcElement($name, wfMsg('anonymous'));
 277         } else if ( !empty($user_real_name) ) {
 278                 dcElement($name, $user_real_name);
 279         } else {
 280                 # XXX: This shouldn't happen.
 281                 if( empty( $user_name ) ) {
 282                         $user_name = User::whoIs($id);
 283                 }
 284                 dcPageOrString($name, $wgLang->getNsText(NS_USER) . ':' . $user_name, wfMsg('siteuser', $user_name));
 285         }
 286 }
 287
 288 /**
 289  * Takes an arg, for future enhancement with different rights for
 290  * different pages.
 291  * @private
 292  */
 293 function dcRights($article) {
 294
 295         global $wgRightsPage, $wgRightsUrl, $wgRightsText;
 296
 297         if (isset($wgRightsPage) &&
 298                 ($nt = Title::newFromText($wgRightsPage))
 299                 && ($nt->getArticleID() != 0)) {
 300                 dcPage('rights', $nt);
 301         } else if (isset($wgRightsUrl)) {
 302                 dcUrl('rights', $wgRightsUrl);
 303         } else if (isset($wgRightsText)) {
 304                 dcElement('rights', $wgRightsText);
 305         }
 306 }
 307
 308 /**
 309  * @private
 310  */
 311 function ccGetTerms($url) {
 312         global $wgLicenseTerms;
 313
 314         if (isset($wgLicenseTerms)) {
 315                 return $wgLicenseTerms;
 316         } else {
 317                 $known = getKnownLicenses();
 318                 return $known[$url];
 319         }
 320 }
 321
 322 /**
 323  * @private
 324  */
 325 function getKnownLicenses() {
 326
 327         $ccLicenses = array('by', 'by-nd', 'by-nd-nc', 'by-nc',
 328                              'by-nc-sa', 'by-sa');
 329         $ccVersions = array('1.0', '2.0');
 330         $knownLicenses = array();
 331
 332         foreach ($ccVersions as $version) {
 333                 foreach ($ccLicenses as $license) {
 334                         if( $version == '2.0' && substr( $license, 0, 2) != 'by' ) {
 335                                 # 2.0 dropped the non-attribs licenses
 336                                 continue;
 337                         }
 338                         $lurl = "http://creativecommons.org/licenses/{$license}/{$version}/";
 339                         $knownLicenses[$lurl] = explode('-', $license);
 340                         $knownLicenses[$lurl][] = 're';
 341                         $knownLicenses[$lurl][] = 'di';
 342                         $knownLicenses[$lurl][] = 'no';
 343                         if (!in_array('nd', $knownLicenses[$lurl])) {
 344                                 $knownLicenses[$lurl][] = 'de';
 345                         }
 346                 }
 347         }
 348
 349         /* Handle the GPL and LGPL, too. */
 350
 351         $knownLicenses['http://creativecommons.org/licenses/GPL/2.0/'] =
 352                 array('de', 're', 'di', 'no', 'sa', 'sc');
 353         $knownLicenses['http://creativecommons.org/licenses/LGPL/2.1/'] =
 354                 array('de', 're', 'di', 'no', 'sa', 'sc');
 355         $knownLicenses['http://www.gnu.org/copyleft/fdl.html'] =
 356                 array('de', 're', 'di', 'no', 'sa', 'sc');
 357
 358         return $knownLicenses;
 359 }
 360
 361 ?>