danielebarchiesi@4: <?php
danielebarchiesi@4: 
danielebarchiesi@4: /**
danielebarchiesi@4:  * @file
danielebarchiesi@4:  * Functions for querying with SPARQL or extracting triples from an ARC2-style
danielebarchiesi@4:  * data structure.
danielebarchiesi@4:  */
danielebarchiesi@4: 
danielebarchiesi@4: function _rdfx_query_ask(&$model, $queries) {
danielebarchiesi@4:   foreach ($queries as $query) {
danielebarchiesi@4:     list($s, $p, $o) = $query;
danielebarchiesi@4:     if (_rdfx_query_find_first($model, $s, $p, $o)) return true;
danielebarchiesi@4:   }
danielebarchiesi@4:   return false;
danielebarchiesi@4: }
danielebarchiesi@4: 
danielebarchiesi@4: function _rdfx_query_find_literal(&$model, $queries) {
danielebarchiesi@4:   $literal = array();
danielebarchiesi@4:   foreach ($queries as $query) {
danielebarchiesi@4:     list($s, $p, $o) = $query;
danielebarchiesi@4:     $triples = _rdfx_query_find_all($model, $s, $p, $o);
danielebarchiesi@4:     // We create an associative array based on the language code of the
danielebarchiesi@4:     // literal. The language codes Drupal uses are specified in includes/iso.inc.
danielebarchiesi@4:     foreach ($triples as $triple) {
danielebarchiesi@4:       if ($triple['o_lang'] !== '') {
danielebarchiesi@4:         // Chinese and Portuguese are the only languages with a >2 letter
danielebarchiesi@4:         // langcode.
danielebarchiesi@4:         if (preg_match('/(zh-hans)|(zh-hant)|(pt-pt)|(pt-br)/', $triple['o_lang'])) {
danielebarchiesi@4:           $langcode = $triple['o_lang'];
danielebarchiesi@4:         }
danielebarchiesi@4:         // Remove the region code if it is used (i.e. en-US is changed to en).
danielebarchiesi@4:         else {
danielebarchiesi@4:           $lang_array = explode('-', $triple['o_lang']);
danielebarchiesi@4:           $langcode = !empty($lang_array[0]) ? $lang_array[0] : $triple['o_lang'];
danielebarchiesi@4:         }
danielebarchiesi@4:       }
danielebarchiesi@4:       else {
danielebarchiesi@4:         $langcode = 'und';
danielebarchiesi@4:       }
danielebarchiesi@4:       $literal[$langcode] = $triple['o'];
danielebarchiesi@4:     }
danielebarchiesi@4:   }
danielebarchiesi@4:   return $literal;
danielebarchiesi@4: }
danielebarchiesi@4: 
danielebarchiesi@4: function _rdfx_query_find_uris(&$model, $queries) {
danielebarchiesi@4:   $uris = array();
danielebarchiesi@4:   foreach ($queries as $query) {
danielebarchiesi@4:     list($s, $p, $o) = $query;
danielebarchiesi@4:     $result = _rdfx_query_find_all($model, $s, $p, $o);
danielebarchiesi@4:     foreach ($result as $triple) {
danielebarchiesi@4:       if ($s == '?' && $triple['s_type'] == 'uri') {
danielebarchiesi@4:         $uris[] = $triple['s'];
danielebarchiesi@4:       }
danielebarchiesi@4:       if ($p == '?') {
danielebarchiesi@4:         $uris[] = $triple['p'];
danielebarchiesi@4:       }
danielebarchiesi@4:       if ($o == '?' && $triple['o_type'] == 'uri') {
danielebarchiesi@4:         $uris[] = $triple['o'];
danielebarchiesi@4:       }
danielebarchiesi@4:     }
danielebarchiesi@4:   }
danielebarchiesi@4:   return array_unique($uris);
danielebarchiesi@4: }
danielebarchiesi@4: 
danielebarchiesi@4: function _rdfx_query_find_qnames(&$model, $queries) {
danielebarchiesi@4:   $uris = _rdfx_query_find_uris($model, $queries);
danielebarchiesi@4:   $qnames = array();
danielebarchiesi@4:   foreach ($uris as $uri) {
danielebarchiesi@4:     $qnames[] = $uri;
danielebarchiesi@4:   }
danielebarchiesi@4:   return $qnames;
danielebarchiesi@4: }
danielebarchiesi@4: 
danielebarchiesi@4: function _rdfx_query_find_first(&$model, $s, $p, $o) {
danielebarchiesi@4:   foreach ($model as $triple) {
danielebarchiesi@4:     if (!is_null($s) && $s != '?' && ($triple['s'] != $s || $triple['s_type'] != 'uri')) continue;
danielebarchiesi@4:     if (!is_null($p) && $p != '?' && ($triple['p'] != $p)) continue;
danielebarchiesi@4:     if (!is_null($o) && $o != '?' && ($triple['o'] != $o || $triple['o_type'] != 'uri')) continue;
danielebarchiesi@4:     return $triple;
danielebarchiesi@4:   }
danielebarchiesi@4:   return null;
danielebarchiesi@4: }
danielebarchiesi@4: 
danielebarchiesi@4: function _rdfx_query_find_all(&$model, $s, $p, $o) {
danielebarchiesi@4:   $result = array();
danielebarchiesi@4:   foreach ($model as $triple) {
danielebarchiesi@4:     if (!is_null($s) && $s != '?' && ($triple['s'] != $s)) continue;
danielebarchiesi@4:     if (!is_null($p) && $p != '?' && ($triple['p'] != $p)) continue;
danielebarchiesi@4:     if (!is_null($o) && $o != '?' && ($triple['o'] != $o)) continue;
danielebarchiesi@4:     $result[] = $triple;
danielebarchiesi@4:   }
danielebarchiesi@4:   return $result;
danielebarchiesi@4: }