/**
* Fetch all subobjects for a given subject using a lazy-mapping iterator
* in order to only resolve one subobject per iteration step.
*
* @since 2.5
*
* @param DIWikiPage $subject
*
* @return MappingIterator
*/
private function newMappingIterator(DIWikiPage $subject)
{
$callback = function ($row) use($subject) {
// #1955
if ($subject->getNamespace() === SMW_NS_PROPERTY) {
$property = new DIProperty($subject->getDBkey());
$subobject = $property->getCanonicalDiWikiPage($row->smw_subobject);
} else {
$subobject = new DIWikiPage($subject->getDBkey(), $subject->getNamespace(), $subject->getInterwiki(), $row->smw_subobject);
}
$subobject->setSortKey($row->smw_sortkey);
$subobject->setId($row->smw_id);
return $subobject;
};
return $this->iteratorFactory->newMappingIterator($this->newResultIterator($subject), $callback);
}
