includes/Metadata.php

   1 <?php
   2 /* Metadata.php -- provides DublinCore and CreativeCommons metadata
   3  * Copyright 2004, Evan Prodromou <evan@wikitravel.org>.
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 define("RDF_TYPE_PREFS", "application/rdf+xml,text/xml;q=0.7,application/xml;q=0.5,text/rdf;q=0.1");
  21
  22 function wfDublinCoreRdf($article) {
  23
  24         $url = dcReallyFullUrl($article->mTitle);
  25
  26         if (rdfSetup()) {
  27                 dcPrologue($url);
  28                 dcBasics($article);
  29                 dcEpilogue();
  30         }
  31 }
  32
  33 function wfCreativeCommonsRdf($article) {
  34
  35         if (rdfSetup()) {
  36                 global $wgRightsUrl;
  37
  38                 $url = dcReallyFullUrl($article->mTitle);
  39
  40                 ccPrologue();
  41                 ccSubPrologue('Work', $url);
  42                 dcBasics($article);
  43                 if (isset($wgRightsUrl)) {
  44                         $url = htmlspecialchars( $wgRightsUrl );
  45                         print "    <cc:license rdf:resource=\"$url\" />\n";
  46                 }
  47
  48                 ccSubEpilogue('Work');
  49
  50                 if (isset($wgRightsUrl)) {
  51                         $terms = ccGetTerms($wgRightsUrl);
  52                         if ($terms) {
  53                                 ccSubPrologue('License', $wgRightsUrl);
  54                                 ccLicense($terms);
  55                                 ccSubEpilogue('License');
  56                         }
  57                 }
  58         }
  59
  60         ccEpilogue();
  61 }
  62
  63 /* private */ function rdfSetup() {
  64         global $wgOut, $wgRdfMimeType, $_SERVER;
  65
  66         $rdftype = wfNegotiateType(wfAcceptToPrefs($_SERVER['HTTP_ACCEPT']), wfAcceptToPrefs(RDF_TYPE_PREFS));
  67
  68         if (!$rdftype) {
  69                 wfHttpError(406, "Not Acceptable", wfMsg("notacceptable"));
  70                 return false;
  71         } else {
  72                 $wgOut->disable();
  73                 header( "Content-type: {$rdftype}" );
  74                 $wgOut->sendCacheControl();
  75                 return true;
  76         }
  77 }
  78
  79 /* private */ function dcPrologue($url) {
  80         global $wgOutputEncoding;
  81
  82         $url = htmlspecialchars( $url );
  83         print "<" . "?xml version=\"1.0\" encoding=\"{$wgOutputEncoding}\" ?" . ">
  84
  85 <!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\">
  86
  87 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
  88          xmlns:dc=\"http://purl.org/dc/elements/1.1/\">
  89   <rdf:Description rdf:about=\"$url\">
  90 ";
  91 }
  92
  93 /* private */ function dcEpilogue() {
  94         print "
  95   </rdf:Description>
  96 </rdf:RDF>
  97 ";
  98 }
  99
 100 /* private */ function dcBasics($article) {
 101         global $wgLanguageCode, $wgSitename;
 102
 103         dcElement('title', $article->mTitle->getText());
 104         dcPageOrString('publisher', wfMsg('aboutpage'), $wgSitename);
 105         dcElement('language', $wgLanguageCode);
 106         dcElement('type', 'Text');
 107         dcElement('format', 'text/html');
 108         dcElement('identifier', dcReallyFullUrl($article->mTitle));
 109         dcElement('date', dcDate($article->getTimestamp()));
 110
 111         $last_editor = $article->getUser();
 112
 113         if ($last_editor == 0) {
 114                 dcPerson('creator', 0);
 115         } else {
 116                 dcPerson('creator', $last_editor, $article->getUserText(),
 117                         User::whoIsReal($last_editor));
 118         }
 119
 120         $contributors = $article->getContributors();
 121
 122         foreach ($contributors as $user_parts) {
 123                 dcPerson('contributor', $user_parts[0], $user_parts[1], $user_parts[2]);
 124         }
 125
 126         dcRights($article);
 127 }
 128
 129 /* private */ function ccPrologue() {
 130         global $wgOutputEncoding;
 131
 132         echo "<" . "?xml version='1.0'  encoding='{$wgOutputEncoding}' ?" . ">
 133
 134 <rdf:RDF xmlns:cc=\"http://web.resource.org/cc/\"
 135          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
 136          xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">
 137 ";
 138 }
 139
 140 /* private */ function ccSubPrologue($type, $url) {
 141         $url = htmlspecialchars( $url );
 142         echo "  <cc:{$type} rdf:about=\"{$url}\">\n";
 143 }
 144
 145 /* private */ function ccSubEpilogue($type) {
 146         echo "  </cc:{$type}>\n";
 147 }
 148
 149 /* private */ function ccLicense($terms) {
 150
 151         foreach ($terms as $term) {
 152                 switch ($term) {
 153                 case 're':
 154                         ccTerm('permits', "Reproduction"); break;
 155                 case 'di':
 156                         ccTerm('permits', "Distribution"); break;
 157                 case 'de':
 158                         ccTerm('permits', "DerivativeWorks"); break;
 159                 case 'nc':
 160                         ccTerm('prohibits', "CommercialUse"); break;
 161                 case 'no':
 162                         ccTerm('requires', "Notice"); break;
 163                 case 'by':
 164                         ccTerm('requires', "Attribution"); break;
 165                 case 'sa':
 166                         ccTerm('requires', "ShareAlike"); break;
 167                 case 'sc':
 168                         ccTerm('requires', "SourceCode"); break;
 169                 }
 170         }
 171 }
 172
 173 /* private */ function ccTerm($term, $name) {
 174         print "    <cc:{$term} rdf:resource=\"http://web.resource.org/cc/{$name}\" />\n";
 175 }
 176
 177 /* private */ function ccEpilogue() {
 178         echo "</rdf:RDF>\n";
 179 }
 180
 181 /* private */ function dcElement($name, $value) {
 182         $value = htmlspecialchars( $value );
 183         print "    <dc:{$name}>{$value}</dc:{$name}>\n";
 184 }
 185
 186 /* private */ function dcDate($timestamp) {
 187         return substr($timestamp, 0, 4) . "-"
 188                 . substr($timestamp, 4, 2) . "-"
 189                 . substr($timestamp, 6, 2);
 190 }
 191
 192 /* private */ function dcReallyFullUrl($title) {
 193         return $title->getFullURL();
 194 }
 195
 196 /* private */ function dcPageOrString($name, $page, $str) {
 197         $nt = Title::newFromText($page);
 198
 199         if (!$nt || $nt->getArticleID() == 0) {
 200                 dcElement($name, $str);
 201         } else {
 202                 dcPage($name, $nt);
 203         }
 204 }
 205
 206 /* private */ function dcPage($name, $title) {
 207         dcUrl($name, dcReallyFullUrl($title));
 208 }
 209
 210 /* private */ function dcUrl($name, $url) {
 211         $url = htmlspecialchars( $url );
 212         print "    <dc:{$name} rdf:resource=\"{$url}\" />\n";
 213 }
 214
 215 /* private */ function dcPerson($name, $id, $user_name="", $user_real_name="") {
 216         global $wgLang;
 217
 218         if ($id == 0) {
 219                 dcElement($name, wfMsg("anonymous"));
 220         } else if ( !empty($user_real_name) ) {
 221                 dcElement($name, $user_real_name);
 222         } else {
 223                 # XXX: This shouldn't happen.
 224                 if( empty( $user_name ) ) {
 225                         $user_name = User::whoIs($id);
 226                 }
 227                 dcPageOrString($name, $wgLang->getNsText(NS_USER) . ":" . $user_name, wfMsg("siteuser", $user_name));
 228         }
 229 }
 230
 231 /* Takes an arg, for future enhancement with different rights for
 232  different pages. */
 233
 234 /* private */ function dcRights($article) {
 235
 236         global $wgRightsPage, $wgRightsUrl, $wgRightsText;
 237
 238         if (isset($wgRightsPage) &&
 239                 ($nt = Title::newFromText($wgRightsPage))
 240                 && ($nt->getArticleID() != 0)) {
 241                 dcPage('rights', $nt);
 242         } else if (isset($wgRightsUrl)) {
 243                 dcUrl('rights', $wgRightsUrl);
 244         } else if (isset($wgRightsText)) {
 245                 dcElement('rights', $wgRightsText);
 246         }
 247 }
 248
 249 /* private */ function ccGetTerms($url) {
 250         global $wgLicenseTerms;
 251
 252         if (isset($wgLicenseTerms)) {
 253                 return $wgLicenseTerms;
 254         } else {
 255                 $known = getKnownLicenses();
 256                 return $known[$url];
 257         }
 258 }
 259
 260 /* private */ function getKnownLicenses() {
 261
 262         $ccLicenses = array('by', 'by-nd', 'by-nd-nc', 'by-nc',
 263                              'by-nc-sa', 'by-sa');
 264         $ccVersions = array('1.0', '2.0');
 265         $knownLicenses = array();
 266
 267         foreach ($ccVersions as $version) {
 268                 foreach ($ccLicenses as $license) {
 269                         if( $version == '2.0' && substr( $license, 0, 2) != 'by' ) {
 270                                 # 2.0 dropped the non-attribs licenses
 271                                 continue;
 272                         }
 273                         $lurl = "http://creativecommons.org/licenses/{$license}/{$version}/";
 274                         $knownLicenses[$lurl] = explode('-', $license);
 275                         $knownLicenses[$lurl][] = 're';
 276                         $knownLicenses[$lurl][] = 'di';
 277                         $knownLicenses[$lurl][] = 'no';
 278                         if (!in_array('nd', $knownLicenses[$lurl])) {
 279                                 $knownLicenses[$lurl][] = 'de';
 280                         }
 281                 }
 282         }
 283
 284         /* Handle the GPL and LGPL, too. */
 285
 286         $knownLicenses["http://creativecommons.org/licenses/GPL/2.0/"] =
 287                 array('de', 're', 'di', 'no', 'sa', 'sc');
 288         $knownLicenses["http://creativecommons.org/licenses/LGPL/2.1/"] =
 289                 array('de', 're', 'di', 'no', 'sa', 'sc');
 290         $knownLicenses["http://www.gnu.org/copyleft/fdl.html"] =
 291                 array('de', 're', 'di', 'no', 'sa', 'sc');
 292
 293         return $knownLicenses;
 294 }
 295
 296 ?>