File: /home/e/l/i/eliteafr/pmb/classes/rdf/arc2/extractors/ARC2_ErdfExtractor.php
<?php
/*
homepage: http://arc.semsol.org/
license: http://arc.semsol.org/license
class: ARC2 eRDF Extractor (w/o link title generation)
author: Benjamin Nowack
version: 2010-11-16
*/
ARC2::inc('RDFExtractor');
class ARC2_ErdfExtractor extends ARC2_RDFExtractor {
function __construct($a, &$caller) {
parent::__construct($a, $caller);
}
function __init() {
parent::__init();
}
/* */
function extractRDF() {
if (!isset($this->caller->detected_formats['erdf'])) return 0;
$root_node = $this->getRootNode();
$base = $this->getDocBase();
$ns = $this->getNamespaces();
$context = array(
'base' => $base,
'prev_res' => $base,
'cur_res' => $base,
'ns' => $ns,
'lang' => '',
);
$this->processNode($root_node, $context);
}
/* */
function getRootNode() {
foreach ($this->nodes as $id => $node) {
if ($node['tag'] == 'html') {
return $node;
}
}
return $this->nodes[0];
}
function getNamespaces() {
$r = array(
'rdf' => 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
'rdfs' => 'http://www.w3.org/2000/01/rdf-schema#'
);
foreach ($this->nodes as $id => $node) {
if (preg_match('/^(link|a)$/', $node['tag']) && isset($node['a']['rel']) && preg_match('/schema\.([^\s]+)/is', $node['a']['rel'], $m) && isset($node['a']['href uri'])) {
$r[$m[1]] = $node['a']['href uri'];
}
}
return $r;
}
/* */
function processNode($n, $ct) {
/* context */
//$ct['lang'] = $this->v('xml:lang', $ct['lang'], $n['a']);
$ct['lang'] = '';
$ct['prop_uris'] = $this->getPropertyURIs($n, $ct);
$ct['prev_res'] = $ct['cur_res'];
$ct['cur_res'] = $this->getCurrentResourceURI($n, $ct);
$ct['cur_obj_id'] = $this->getCurrentObjectID($n, $ct);
$ct['cur_obj_literal'] = $this->getCurrentObjectLiteral($n, $ct);
/* triple production (http://research.talis.com/2005/erdf/wiki/Main/SummaryOfTripleProductionRules) */
foreach ($ct['prop_uris'] as $type => $uris) {
foreach ($uris as $uri) {
$rdf_type = preg_match('/^ /', $uri) ? 1 : 0;
/* meta + name */
if (($type == 'name') && ($n['tag'] == 'meta')) {
$t = array(
's' => $ct['cur_res'],
's_type' => 'uri',
'p' => $uri,
'o' => $ct['cur_obj_literal']['value'],
'o_type' => 'literal',
'o_lang' => $ct['cur_obj_literal']['datatype'] ? '' : $ct['cur_obj_literal']['lang'],
'o_datatype' => $ct['cur_obj_literal']['datatype'],
);
$this->addT($t);
}
/* class */
if ($type == 'class') {
if ($rdf_type) {
$s = $this->v('href uri', $ct['cur_res'], $n['a']);
$s = $this->v('src uri', $s, $n['a']);
$t = array(
's' => $s,
's_type' => 'uri',
'p' => $ct['ns']['rdf'] . 'type',
'o' => trim($uri),
'o_type' => 'uri',
'o_lang' => '',
'o_datatype' => '',
);
}
elseif (isset($n['a']['id'])) {/* used as object */
$t = array(
's' => $ct['prev_res'],
's_type' => 'uri',
'p' => $uri,
'o' => $ct['cur_res'],
'o_type' => 'uri',
'o_lang' => '',
'o_datatype' => '',
);
}
else {
$t = array(
's' => $ct['cur_res'],
's_type' => 'uri',
'p' => $uri,
'o' => $ct['cur_obj_literal']['value'],
'o_type' => 'literal',
'o_lang' => $ct['cur_obj_literal']['datatype'] ? '' : $ct['cur_obj_literal']['lang'],
'o_datatype' => $ct['cur_obj_literal']['datatype'],
);
if (($o = $this->v('src uri', '', $n['a'])) || ($o = $this->v('href uri', '', $n['a']))) {
if (!$ct['prop_uris']['rel'] && !$ct['prop_uris']['rev']) {
$t['o'] = $o;
$t['o_type'] = 'uri';
$t['o_lang'] = '';
$t['o_datatype'] = '';
}
}
}
$this->addT($t);
}
/* rel */
if ($type == 'rel') {
if (($o = $this->v('src uri', '', $n['a'])) || ($o = $this->v('href uri', '', $n['a']))) {
$t = array(
's' => $ct['cur_res'],
's_type' => 'uri',
'p' => $uri,
'o' => $o,
'o_type' => 'uri',
'o_lang' => '',
'o_datatype' => '',
);
$this->addT($t);
}
}
/* rev */
if ($type == 'rev') {
if (($s = $this->v('src uri', '', $n['a'])) || ($s = $this->v('href uri', '', $n['a']))) {
$t = array(
's' => $s,
's_type' => 'uri',
'p' => $uri,
'o' => $ct['cur_res'],
'o_type' => 'uri',
'o_lang' => '',
'o_datatype' => '',
);
$this->addT($t);
}
}
}
}
/* imgs */
if ($n['tag'] == 'img') {
if (($s = $this->v('src uri', '', $n['a'])) && $ct['cur_obj_literal']['value']) {
$t = array(
's' => $s,
's_type' => 'uri',
'p' => $ct['ns']['rdfs'] . 'label',
'o' => $ct['cur_obj_literal']['value'],
'o_type' => 'literal',
'o_lang' => $ct['cur_obj_literal']['datatype'] ? '' : $ct['cur_obj_literal']['lang'],
'o_datatype' => $ct['cur_obj_literal']['datatype'],
);
$this->addT($t);
}
}
/* anchors */
if ($n['tag'] == 'a') {
if (($s = $this->v('href uri', '', $n['a'])) && $ct['cur_obj_literal']['value']) {
$t = array(
's' => $s,
's_type' => 'uri',
'p' => $ct['ns']['rdfs'] . 'label',
'o' => $ct['cur_obj_literal']['value'],
'o_type' => 'literal',
'o_lang' => $ct['cur_obj_literal']['datatype'] ? '' : $ct['cur_obj_literal']['lang'],
'o_datatype' => $ct['cur_obj_literal']['datatype'],
);
$this->addT($t);
}
}
/* recurse */
if ($n['tag'] == 'a') {
$ct['cur_res'] = $ct['cur_obj_id'];
}
$sub_nodes = $this->getSubNodes($n);
foreach ($sub_nodes as $sub_node) {
$this->processNode($sub_node, $ct);
}
}
/* */
function getPropertyURIs($n, $ct) {
$r = array();
foreach (array('rel', 'rev', 'class', 'name', 'src') as $type) {
$r[$type] = array();
$vals = $this->v($type . ' m', array(), $n['a']);
foreach ($vals as $val) {
if (!trim($val)) continue;
list($uri, $sub_v) = $this->xQname(trim($val, '- '), $ct['base'], $ct['ns'], $type);
if (!$uri) continue;
$rdf_type = preg_match('/^-/', trim($val)) ? 1 : 0;
$r[$type][] = $rdf_type ? ' ' . $uri : $uri;
}
}
return $r;
}
function getCurrentResourceURI($n, $ct) {
if (isset($n['a']['id'])) {
list($r, $sub_v) = $this->xURI('#' . $n['a']['id'], $ct['base'], $ct['ns']);
return $r;
}
return $ct['cur_res'];
}
function getCurrentObjectID($n, $ct) {
foreach (array('href', 'src') as $a) {
if (isset($n['a'][$a])) {
list($r, $sub_v) = $this->xURI($n['a'][$a], $ct['base'], $ct['ns']);
return $r;
}
}
return $this->createBnodeID();
}
function getCurrentObjectLiteral($n, $ct) {
$r = array('value' => '', 'lang' => $ct['lang'], 'datatype' => '');
if (isset($n['a']['content'])) {
$r['value'] = $n['a']['content'];
}
elseif (isset($n['a']['title'])) {
$r['value'] = $n['a']['title'];
}
else {
$r['value'] = $this->getPlainContent($n);
}
return $r;
}
/* */
function xURI($v, $base, $ns, $attr_type = '') {
if ((list($sub_r, $sub_v) = $this->xQname($v, $base, $ns)) && $sub_r) {
return array($sub_r, $sub_v);
}
if (preg_match('/^(rel|rev|class|name)$/', $attr_type) && preg_match('/^[a-z0-9]+$/', $v)) {
return array(0, $v);
}
return array($this->calcURI($v, $base), '');
}
function xQname($v, $base, $ns) {
if ($sub_r = $this->x('([a-z0-9\-\_]+)[\-\.]([a-z0-9\-\_]+)', $v)) {
if (isset($ns[$sub_r[1]])) {
return array($ns[$sub_r[1]] . $sub_r[2], '');
}
}
return array(0, $v);
}
/* */
}