diff --git a/jsonld.php b/jsonld.php
index 6cfb487..f095e03 100644
--- a/jsonld.php
+++ b/jsonld.php
@@ -610,6 +610,7 @@ class JsonLdProcessor {
const XSD_STRING = 'http://www.w3.org/2001/XMLSchema#string';
/** RDF constants */
+ const RDF_LIST = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#List';
const RDF_FIRST = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#first';
const RDF_REST = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#rest';
const RDF_NIL = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#nil';
@@ -2431,7 +2432,11 @@ class JsonLdProcessor {
$ids = array_keys((array)$node_map);
sort($ids);
foreach($ids as $id) {
- $subject->{'@graph'}[] = $node_map->{$id};
+ $node = $node_map->{$id};
+ // only add full subjects
+ if(!self::_isSubjectReference($node)) {
+ $subject->{'@graph'}[] = $node;
+ }
}
}
@@ -2440,7 +2445,11 @@ class JsonLdProcessor {
$keys = array_keys((array)$default_graph);
sort($keys);
foreach($keys as $key) {
- $flattened[] = $default_graph->{$key};
+ $node = $default_graph->{$key};
+ // only add full subjects to top-level
+ if(self::_isSubjectReference($node)) {
+ $flattened[] = $node;
+ }
}
return $flattened;
}
@@ -2665,8 +2674,7 @@ class JsonLdProcessor {
$node = $node_map->{$s};
$object_is_id = ($o->type === 'IRI' || $o->type === 'blank node');
- if($object_is_id && $o->value !== self::RDF_NIL &&
- !property_exists($node_map, $o->value)) {
+ if($object_is_id && !property_exists($node_map, $o->value)) {
$node_map->{$o->value} = (object)array('@id' => $o->value);
}
@@ -2676,90 +2684,94 @@ class JsonLdProcessor {
continue;
}
- if($object_is_id &&
- $o->value === self::RDF_NIL && $p !== self::RDF_REST) {
- // empty list detected
- $value = (object)array('@list' => array());
- }
- else {
- $value = self::_RDFToObject($o, $options['useNativeTypes']);
- }
+ $value = self::_RDFToObject($o, $options['useNativeTypes']);
self::addValue($node, $p, $value, array('propertyIsArray' => true));
- // object may be the head of an RDF list but we can't know easily
- // until all triples are read
- if($o->type === 'blank node' &&
- !($p === self::RDF_FIRST || $p === self::RDF_REST)) {
+ // object may be an RDF list/partial list node but we can't know
+ // easily until all triples are read
+ if($object_is_id) {
$object = $node_map->{$o->value};
- if(!property_exists($object, 'listHeadFor')) {
- $object->listHeadFor = $value;
- }
- // can't be a list head if referenced more than once
- else {
- $object->listHeadFor = null;
+ if(!property_exists($object, 'usages')) {
+ $object->usages = array();
}
+ $object->usages[] = (object)array(
+ 'node' => $node,
+ 'property' => $p,
+ 'value' => $value);
}
}
}
// convert linked lists to @list arrays
foreach($graph_map as $name => $graph_object) {
- foreach($graph_object as $subject => $node) {
- // if subject not in graph_object, it has been removed as it was
- // part of an RDF list, continue
- if(!property_exists($graph_object, $subject)) {
- continue;
- }
- // if value is not an object, it can't be a list head, continue
- $value = (property_exists($node, 'listHeadFor') ?
- $node->listHeadFor : null);
- if(!is_object($value)) {
- continue;
- }
+ // no @lists to be converted, continue
+ if(!property_exists($graph_object, self::RDF_NIL)) {
+ continue;
+ }
- $list = array();
- $eliminated_nodes = new stdClass();
- while($subject !== self::RDF_NIL && $list !== null) {
- // ensure node is a valid list node; node must:
- // 1. Be a blank node
- // 2. Have no keys other than: @id, listHeadFor, rdf:first, rdf:rest.
- // 3. Have an array for rdf:first that has 1 item.
- // 4. Have an array for rdf:rest that has 1 object with @id.
- // 5. Not already be in a list (it is in the eliminated nodes map).
- $node_key_count = (is_object($node) ?
- count(array_keys((array)$node)) : 0);
- if(!(is_object($node) && strpos($node->{'@id'}, '_:') === 0 &&
- ($node_key_count === 3 || ($node_key_count === 4 &&
- property_exists($node, 'listHeadFor'))) &&
- property_exists($node, self::RDF_FIRST) &&
- property_exists($node, self::RDF_REST) &&
- is_array($node->{self::RDF_FIRST}) &&
- count($node->{self::RDF_FIRST}) === 1 &&
- is_array($node->{self::RDF_REST}) &&
- count($node->{self::RDF_REST}) === 1 &&
- is_object($node->{self::RDF_REST}[0]) &&
- property_exists($node->{self::RDF_REST}[0], '@id') &&
- !property_exists($eliminated_nodes, $subject))) {
- $list = null;
+ // iterate backwards through each RDF list
+ $nil = $graph_object->{self::RDF_NIL};
+ foreach($nil->usages as $usage) {
+ $node = $usage->node;
+ $property = $usage->property;
+ $head = $usage->value;
+ $list = [];
+ $list_nodes = [];
+
+ // ensure node is a well-formed list node; it must:
+ // 1. Be used only once in a list.
+ // 2. Have an array for rdf:first that has 1 item.
+ // 3. Have an array for rdf:rest that has 1 item.
+ // 4. Have no keys other than: @id, usages, rdf:first, rdf:rest, and,
+ // optionally, @type where the value is rdf:List.
+ $node_key_count = count(array_keys((array)$node));
+ while($property === self::RDF_REST && count($node->usages) === 1 &&
+ property_exists($node, self::RDF_FIRST) &&
+ property_exists($node, self::RDF_REST) &&
+ is_array($node->{self::RDF_FIRST}) &&
+ is_array($node->{self::RDF_REST}) &&
+ count($node->{self::RDF_FIRST}) === 1 &&
+ count($node->{self::RDF_REST}) === 1 &&
+ ($node_key_count === 4 || ($node_key_count === 5 &&
+ property_exists($node, '@type') && is_array($node->{'@type'}) &&
+ count($node->{'@type'}) === 1 &&
+ $node->{'@type'}[0] === self::RDF_LIST))) {
+ $list[] = $node->{self::RDF_FIRST}[0];
+ $list_nodes[] = $node->{'@id'};
+
+ // get next node, moving backwards through list
+ $usage = $node->usages[0];
+ $node = $usage->node;
+ $property = $usage->property;
+ $head = $usage->value;
+ $node_key_count = count(array_keys((array)$node));
+
+ // if node is not a blank node, then list head found
+ if(strpos($node->{'@id'}, '_:') !== 0) {
break;
}
-
- $list[] = $node->{self::RDF_FIRST}[0];
- $eliminated_nodes->{$node->{'@id'}} = true;
- $subject = $node->{self::RDF_REST}[0]->{'@id'};
- $node = (property_exists($graph_object, $subject) ?
- $graph_object->{$subject} : null);
}
- // bad list detected, skip it
- if($list === null) {
- continue;
+ // list is nested in another list
+ if($property === self::RDF_FIRST) {
+ // empty list
+ if($node->{'@id'} === self::RDF_NIL) {
+ // can't convert rdf:nil to a @list object because it would
+ // result in a list of lists which isn't supported
+ continue;
+ }
+
+ // preserve list head
+ $head = $graph_object->{$head->{'@id'}}->{self::RDF_REST}[0];
+ array_pop($list);
+ array_pop($list_nodes);
}
- unset($value->{'@id'});
- $value->{'@list'} = $list;
- foreach($eliminated_nodes as $id => $b) {
- unset($graph_object->{$id});
+ // transform list into @list object
+ unset($head->{'@id'});
+ $head->{'@list'} = array_reverse($list);
+ foreach($list_nodes as $list_node) {
+ unset($graph_object->{$list_node});
}
}
}
@@ -2776,14 +2788,14 @@ class JsonLdProcessor {
sort($subjects_);
foreach($subjects_ as $subject_) {
$node_ = $graph_object->{$subject_};
- unset($node_->listHeadFor);
+ unset($node_->usages);
// only add full subjects to top-level
if(!self::_isSubjectReference($node_)) {
$node->{'@graph'}[] = $node_;
}
}
}
- unset($node->listHeadFor);
+ unset($node->usages);
// only add full subjects to top-level
if(!self::_isSubjectReference($node)) {
$result[] = $node;