Multiple XML sub-elements not supported

[pchampin]

With an XML/XPath logical source, if the iterated element has several sub-elements matching a given reference, only the first one is considered.

Example data:

<?xml version="1.0"?>

<persons>
  <person>
    <fname>Bob</fname>
    <likes>music</likes>
  </person>
  <person>
    <fname>Sue</fname>
    <likes>tennis</likes>
    <likes>chess</likes>
  </person>
</persons>

Example mapping:

@prefix ex: <http://example.com/> .
@prefix rml: <http://w3id.org/rml/> .

<http://example.com/base/TriplesMap1> a rml:TriplesMap;
  rml:logicalSource [ a rml:LogicalSource;
      rml:source [ a rml:RelativePathSource;
          rml:root rml:MappingDirectory;
          rml:path "ious.xml"
        ];
      rml:referenceFormulation rml:XPath;
      rml:iterator "/persons/person";
    ];
  rml:subjectMap [
      rml:template "http://example.com/p/{fname}";
    ];
  rml:predicateObjectMap [
      rml:predicate ex:likes;
      rml:objectMap [
          rml:reference "likes"
        ];
   ];
.

Expected result:

<http://example.com/p/Bob> <http://example.com/likes> "music" .
<http://example.com/p/Sue> <http://example.com/likes> "tennis" .
<http://example.com/p/Sue> <http://example.com/likes> "chess" .

Obtained result:

<http://example.com/p/Bob> <http://example.com/likes> "music" .
<http://example.com/p/Sue> <http://example.com/likes> "tennis" .