Hello Frédéric
I have a somewhat philosophical question for you. I have been reported
that the "xlink:href" attribute were sometime lost when marshalling a
metadata object to XML. In my understanding, that attribute is used for
replacing a verbose definition. For example instead of:
<gmd:citation>
<gmd:CI_Citation>
<gmd:responsibleParty>
<gmd:CI_ResponsibleParty>
<gmd:organisationName>
Apache
... etc for a very long XML
one could write for instance:
<gmd:citation xlink:href="http://...#apache"/>
Where the URL is a link to an other XML document containing the complete
<gmd:CI_Citation> definition. In the current Apache SIS implementation,
those two representations are mutually exclusive. The rational was that
when a xlink:href is provided, the normal intend is to not marshal the
complete element below it, otherwise the xlink:href would be pointless.
This raise the question of what to do when both xlink:href and a
metadata definition are provided. In current implementation, SIS uses
the xlink:href form only if the user has explicitly flagged his metadata
object has "nil" by implementing the NilObject interface [1]. If a
metadata object is non-nil, then SIS conservatively marshal the whole
object instead, no matter if a xlink:href is defined or not. It would be
technically easy to both marshal the whole object and to write the
xlink:href attribute, but I'm not sure if it make sense to do that in
every cases (xlink:href are not identifiers - there is other attributes
for the later).
Actually the user has control on whether to marshal the whole metadata
or only xlink:href (but currently no control on whether SIS should
marshal both together) by overriding the ReferenceResolver method. My
question is about what should be the default behaviour?
Martin
[1] http://sis.apache.org/apidocs/org/apache/sis/xml/NilObject.html
[2]
http://sis.apache.org/apidocs/org/apache/sis/xml/ReferenceResolver.html#canSubstituteByReference%28org.apache.sis.xml.MarshalContext,%20java.lang.Class,%20T,%20org.apache.sis.xml.XLink%29
