1 <?php // rcs_id('$Id$');
3 * What to do on ?format=rdf What to do on ?format=owl
5 * Map relations on a wikipage to a RDF ressource to build a "Semantic Web"
6 * - a web ontology frontend compatible to OWL (web ontology language).
7 * http://www.w3.org/2001/sw/Activity
8 * Simple RDF ontologies contain facts and rules, expressed by RDF triples:
9 * Subject (page) -> Predicate (verb, relation) -> Object (links)
10 * OWL extents that to represent a typical OO framework.
14 * subClassOf, restrictedBy, onProperty, intersectionOf, allValuesFrom, ...
15 * someValuesFrom, unionOf, equivalentClass, disjointWith, ...
16 * plus the custom vocabulary (ontology): canRun, canBite, smellsGood, ...
17 * OWL Subjects: Class, Restriction, ...
18 * OWL Properties: type, label, comment, ...
19 * DAML should also be supported.
22 * - Another way to represent various KB models in various DL languages.
24 * - Frontend to various KB model reasoners and representations.
25 * - Generation/update of static wiki pages based on external OWL/DL/KB
26 * (=> ModelTest/Categories)
27 * KB Blackboard and Visualization.
28 * - OWL generation based on static wiki pages (ModelTest?format=owl)
30 * Facts: (may be represented by special links on a page)
31 * - Each page must be representable with an unique URL.
32 * - Each fact must be representable with an unique RDF triple.
33 * - A class is represented by a category page.
34 * - To represent more expressive description logic, "enriched"
35 * links will not be enough (? variable symbolic objects).
37 * Rules: (may be represented by special content on a page)
38 * - Syntax: reasoner backend specific, or common or ?
40 * RDF Triple: (representing facts)
41 * Subject (page) -> Predicate (verb, relation) -> Object (links)
44 * Special link qualifiers represent RDF triples, based on RDF standard notation.
45 * See RDF standard DTD's on daml.org and w3.org, plus your custom predicates.
47 * Example: page [Ape] isa:Animal, ...
48 * Object: special links on a page.
50 * Model: Basepage for a KB. (parametrizeable pages or copies of modified snapshots?)
52 * DL: Description Logic
56 * Of course *real* expert systems ("reasoners") will help/must be used in
57 * optimization and maintainance of the SemanticWeb KB (Knowledge
58 * Base). Hooks will be tested to KM (an interactive KB playground),
59 * LISA (standard unifier), FaCT, RACER, ...
61 * Maybe also ZEBU (parser generator) is needed to convert the wiki KB
62 * syntax to the KB reasoner backend (LISA, KM, CLIPS, JESS, FaCT,
65 * pOWL is a simple php backend with some very simple AI logic in PHP,
66 * though I strongly doubt the usefulness of reasoners not written in
69 * SEAL (omntoweb.org) is similar to that, just on top of the Zope CMF.
70 * FaCT uses e.g. this KB DTD:
71 <!ELEMENT KNOWLEDGEBASE (DEFCONCEPT|DEFROLE|IMPLIESC|EQUALC|IMPLIESR|EQUALR|TRANSITIVE|FUNCTIONAL)*>
72 <!ELEMENT CONCEPT (PRIMITIVE|TOP|BOTTOM|AND|OR|NOT|SOME|ALL|ATMOST|ATLEAST)>
73 <!ELEMENT ROLE (PRIMROLE|INVROLE)>
74 ... (facts and rules described in XML)
77 * http://phpwiki.org/SemanticWeb,
78 * http://en.wikipedia.org/wiki/Knowledge_representation
79 * http://www.ontoweb.org/
80 * http://www.semwebcentral.org/ (OWL on top of GForge)
83 * Author: Reini Urban <rurban@x-ray.at>
85 /*============================================================================*/
87 Copyright 2004,2007 Reini Urban
89 This file is part of PhpWiki.
91 PhpWiki is free software; you can redistribute it and/or modify
92 it under the terms of the GNU General Public License as published by
93 the Free Software Foundation; either version 2 of the License, or
94 (at your option) any later version.
96 PhpWiki is distributed in the hope that it will be useful,
97 but WITHOUT ANY WARRANTY; without even the implied warranty of
98 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
99 GNU General Public License for more details.
101 You should have received a copy of the GNU General Public License
102 along with PhpWiki; if not, write to the Free Software
103 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
106 require_once('lib/RssWriter.php');
107 require_once('lib/TextSearchQuery.php');
108 require_once('lib/Units.php');
112 * RdfWriter - A class to represent the links of a list of wikipages as RDF.
113 * Supports ?format=rdf
115 * RdfWriter (unsorted)
116 * - RssWriter (timesorted)
117 * - RecentChanges (?action=RecentChanges&format=rdf) (filtered)
119 class RdfWriter extends RssWriter // in fact it should be rewritten to be other way round.
121 function RdfWriter (&$request, &$pagelist) {
122 $this->_request =& $request;
123 $this->_pagelist =& $pagelist;
124 $this->XmlElement('rdf:RDF',
125 array('xmlns' => "http://purl.org/rss/1.0/",
126 'xmlns:rdf' => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'));
128 $this->_modules = array(
130 'content' => "http://purl.org/rss/1.0/modules/content/",
131 'dc' => "http://purl.org/dc/elements/1.1/",
134 $this->_uris_seen = array();
135 $this->_items = array();
137 $this->wiki_xmlns_xml = WikiURL(_("UriResolver")."?",false,true);
138 $this->wiki_xmlns_url = PHPWIKI_BASE_URL;
140 $this->pre_ns_buffer =
141 "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" .
142 "<!DOCTYPE rdf:RDF[\n" .
143 "\t"."<!ENTITY rdf 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>\n" .
144 "\t"."<!ENTITY rdfs 'http://www.w3.org/2000/01/rdf-schema#'>\n" .
145 "\t"."<!ENTITY owl 'http://www.w3.org/2002/07/owl#'>\n" .
146 "\t"."<!ENTITY smw 'http://smw.ontoware.org/2005/smw#'>\n" .
147 "\t"."<!ENTITY smwdt 'http://smw.ontoware.org/2005/smw-datatype#'>\n" .
148 // A note on "wiki": this namespace is crucial as a fallback when it would be illegal to start e.g. with a number. In this case, one can always use wiki:... followed by "_" and possibly some namespace, since _ is legal as a first character.
149 "\t"."<!ENTITY wiki '" . $this->wiki_xmlns_xml . "'>\n" .
150 "\t"."<!ENTITY relation '" . $this->wiki_xmlns_xml .
151 $this->makeXMLExportId(urlencode(str_replace(' ', '_', _("Relation") . ':'))) . "'>\n" .
152 "\t"."<!ENTITY attribute '" . $this->wiki_xmlns_xml .
153 $this->makeXMLExportId(urlencode(str_replace(' ', '_', _("Attribute") . ':'))) . "'>\n" .
154 "\t"."<!ENTITY wikiurl '" . $this->wiki_xmlns_url . "'>\n" .
157 "\t"."xmlns:rdf=\"&rdf;\"\n" .
158 "\t"."xmlns:rdfs=\"&rdfs;\"\n" .
159 "\t"."xmlns:owl =\"&owl;\"\n" .
160 "\t"."xmlns:smw=\"&smw;\"\n" .
161 "\t"."xmlns:wiki=\"&wiki;\"\n" .
162 "\t"."xmlns:relation=\"&relation;\"\n" .
163 "\t"."xmlns:attribute=\"&attribute;\"";
164 $this->post_ns_buffer =
165 "\n\t<!-- reference to the Semantic MediaWiki schema -->\n" .
166 "\t"."<owl:AnnotationProperty rdf:about=\"&smw;hasArticle\">\n" .
167 "\t\t"."<rdfs:isDefinedBy rdf:resource=\"http://smw.ontoware.org/2005/smw\"/>\n" .
168 "\t"."</owl:AnnotationProperty>\n" .
169 "\t"."<owl:AnnotationProperty rdf:about=\"&smw;hasType\">\n" .
170 "\t\t"."<rdfs:isDefinedBy rdf:resource=\"http://smw.ontoware.org/2005/smw\"/>\n" .
171 "\t"."</owl:AnnotationProperty>\n" .
172 "\t"."<owl:Class rdf:about=\"&smw;Thing\">\n" .
173 "\t\t"."<rdfs:isDefinedBy rdf:resource=\"http://smw.ontoware.org/2005/smw\"/>\n" .
174 "\t"."</owl:Class>\n" .
175 "\t<!-- exported page data -->\n";
179 header( "Content-type: application/rdf+xml; charset=UTF-8" );
180 echo $this->pre_ns_buffer;
184 $dbi = $this->_request->_dbi;
185 /* Elements per page:
186 out-links internal, out-links external
191 foreach ($this->_pagelist->_pages as $page) {
192 $relation = new TextSearchQuery("*");
193 foreach (array('linkto','linkfrom','relation','attribute') as $linktype) {
194 $linkiter = $dbi->linkSearch($pages, $search, $linktype, $relation);
196 while ($link = $linkiter->next()) {
197 if (mayAccessPage('view', $rev->_pagename)) {
198 $linkto->addItem($this->item_properties($rev),
199 $this->pageURI($rev));
201 $this->setValidators($rev);
207 echo $this->post_ns_buffer;
211 /** This function transforms a valid url-encoded URI into a string
212 * that can be used as an XML-ID. The mapping should be injective.
214 function makeXMLExportId($uri) {
215 $uri = str_replace( '-', '-2D', $uri);
216 //$uri = str_replace( ':', '-3A', $uri); //already done by PHP
217 //$uri = str_replace( '_', '-5F', $uri); //not necessary
218 $uri = str_replace( array('"', '#', '&', "'", '+', '=', '%'),
219 array('-22','-23','-26','-27','-2B','-3D','-'),
224 /** This function transforms an XML-ID string into a valid
225 * url-encoded URI. This is the inverse to makeXMLExportID.
227 function makeURIfromXMLExportId($id) {
228 $id = str_replace( array('-22','-23','-26','-27','-2B','-3D','-'),
229 array('"', '#', '&', "'", '+', '=', '%'),
231 $id = str_replace( '-2D', '-', $id);
238 class RdfsWriter extends RdfWriter {
242 * OwlWriter - A class to represent a set of wiki pages (a DL model) as OWL.
243 * Requires an actionpage returning a pagelist.
244 * Supports ?format=owl
250 class OwlWriter extends RdfWriter {
254 * ModelWriter - Export a KB as set of wiki pages.
255 * Requires an actionpage returning a pagelist.
256 * Probably based on some convenient DL expression syntax. (deffact, defrule, ...)
262 class ModelWriter extends OwlWriter {
266 * NumericSearchQuery can do:
267 * ("population < 20000 and area > 1000000", array("population", "area"))
268 * ->match(array('population' => 100000, 'area' => 10000000))
269 * @see NumericSearchQuery
271 * SemanticAttributeSearchQuery can detect and unify units in numbers.
272 * ("population < 2million and area > 100km2", array("population", "area"))
273 * ->match(array('population' => 100000, 'area' => 10000000))
275 * Do we need a real parser or can we just regexp over some allowed unit
276 * suffixes to detect the numbers?
277 * See man units(1) and /usr/share/units.dat
278 * base units: $ units "1 million miles"
279 * Definition: 1.609344e+09 m
281 class SemanticAttributeSearchQuery
282 extends NumericSearchQuery
285 var $base_units = array('m' => explode(',','km,miles,cm,dm,mm,ft,inch,inches,meter'),
286 'm^2' => explode(',','km^2,ha,cm^2,mi^2'),
287 'm^3' => explode(',','km^3,lit,cm^3,dm^3,gallons'),
292 * We need to detect units from the freetext query:
293 * population > 1 million
295 function SemanticAttributeSearchQuery($search_query, $placeholders, $unit = '') {
296 $this->NumericSearchQuery($search_query, $placeholders);
297 $this->_units = new Units();
302 * Strip non-numeric chars from the variable (as the groupseperator) and replace
303 * it in the symbolic query for evaluation.
304 * This version unifies the attribute values from the database to a
305 * numeric basevalue before comparison. (area:=963.6km^2 => 9.366e+08 m^2)
308 * @param $value number A numerical value: integer, float or string.
309 * @param $x string The variable name to be replaced in the query.
312 function _bind($value, $x) {
314 $value = preg_replace("/,/", "", $value);
315 $this->_bound[] = array('linkname' => $x,
316 'linkvalue' => $value);
317 // We must ensure that the same baseunits are matched against.
318 // We cannot compare m^2 to m or ''
319 $val_base = $this->_units->basevalue($value);
320 if (!DISABLE_UNITS and $this->_units->baseunit($value) != $this->unit) {
321 // Poor user has selected an attribute, but no unit. assume he means the baseunit
322 if (count($this->getVars() == 1) and $this->unit == '') {
325 // non-matching units are silently ignored
326 $this->_workquery = '';
331 if (!is_numeric($value)) {
332 $this->_workquery = ''; //must return false
333 trigger_error("Cannot match against non-numeric attribute value $x := $ori_value",
338 $this->_workquery = preg_replace("/\b".preg_quote($x,"/")."\b/", $value, $this->_workquery);
339 return $this->_workquery;
345 * SemanticSearchQuery can do:
346 * (is_a::city and population < 20000) and (*::city and area > 1000000)
347 * ->match(array('is_a' => 'city', 'linkfrom' => array(),
348 * population' => 100000, 'area' => 10000000))
349 * @return array A list of found and bound matches
351 class SemanticSearchQuery
352 extends SemanticAttributeSearchQuery
354 function hasAttributes() { // TODO
356 function hasRelations() { // TODO
358 function getLinkNames() { // TODO
363 * ReasonerBackend - hooks to reasoner backends.
364 * via http as with DIG,
367 class ReasonerBackend {
368 function ReasonerBackend () {
372 * transform to reasoner syntax
374 function transformTo () {
378 * transform from reasoner syntax
380 function transformFrom () {
391 class ReasonerBackend_LISA extends ReasonerBackend {
394 class ReasonerBackend_Racer extends ReasonerBackend {
397 class ReasonerBackend_KM extends ReasonerBackend {
404 // c-hanging-comment-ender-p: nil
405 // indent-tabs-mode: nil