Keyword selection / add keyword using gmx:Anchor instead of gco:CharacterString

[fxp]

In some metadata profiles, keywords are created using gmx:Anchor instead of gco:CharacterString. It needs basic support for Anchor (See #681) and changes on KeywordBean#getComplexIso19139Elt which is called before adding keywords.

Example:

<gmd:descriptiveKeywords>
	<gmd:MD_Keywords>
		<gmd:keyword>
			<gmx:Anchor xlink:href="http://www.seadatanet.org/urnurl/SDN:P021::ATVS">Atmospheric visibility and transparency</gmx:Anchor>
		</gmd:keyword>
		<gmd:keyword>
			<gmx:Anchor xlink:href="http://www.seadatanet.org/urnurl/SDN:P021::SAGE">Sediment age</gmx:Anchor>
		</gmd:keyword>
		<gmd:type>
			<gmd:MD_KeywordTypeCode codeList="http://www.seadatanet.org/urnurl/codelists.xml#MD_KeywordTypeCode" codeListValue="parameter" codeSpace="http://www.seadatanet.org/urnurl/">parameter</gmd:MD_KeywordTypeCode>
		</gmd:type>
		<gmd:thesaurusName>
			<gmd:CI_Citation>
				<gmd:title>
					<gco:CharacterString>BODC Parameter Discovery Vocabulary</gco:CharacterString>
				</gmd:title>
				<gmd:alternateTitle>
					<gco:CharacterString>P021</gco:CharacterString>
				</gmd:alternateTitle>
				<gmd:date>
					<gmd:CI_Date>
						<gmd:date>
							<gco:Date>2009-06-05</gco:Date>
						</gmd:date>
						<gmd:dateType>
							<gmd:CI_DateTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode" codeListValue="revision" codeSpace="ISOTC211/19115">revision</gmd:CI_DateTypeCode>
						</gmd:dateType>
					</gmd:CI_Date>
				</gmd:date>
				<gmd:edition>
					<gco:CharacterString>41</gco:CharacterString>
				</gmd:edition>
				<gmd:identifier>
					<gmd:MD_Identifier>
						<gmd:code>
							<gco:CharacterString>http://www.seadatanet.org/urnurl/SDN:P021</gco:CharacterString>
						</gmd:code>
					</gmd:MD_Identifier>
				</gmd:identifier>
			</gmd:CI_Citation>
		</gmd:thesaurusName>
	</gmd:MD_Keywords>
</gmd:descriptiveKeywords>

[simonp]

Fixed in commit #9241

[mcoudert]

Keywords selection in the advanced GUI, in the editor, leads to create keywords using gmx:Anchor... Is it an expected behavior in 2.8.0-RC1?

I'm wondering how gmx:Anchor elements are supported in that version because it breaks search on keywords (i.e. computing extent from keywords). Thanks in advance for your reply

[simonp]

I think the idea behind this is that if you going to select a keyword from the thesaurus then you need to be able to recover the exact keyword from the thesaurus - to do this you need the id of that keyword in the thesaurus otherwise you can't really know which one it is (reliably that is) - to do that you would need a gmx:Anchor (or some other substitute) rather than a gco:CharacterString. In what way does it break the computing extent from keywords process (apart from the obviously allowing for both gco:CharacterString and gmx:Anchor)? Just looking at the process xslt I can't see that it would be difficult to make it work with either?

[fxp]

I think that should be a profile configuration. I'm working on a proposal for that which extends the ideas described in the registers proposal by providing a way to use a thesaurus selection for making any ISO elements by defining:

• association: eg. thesaurus A could be used to define ISO element of type gmd:descriptiveKeywords (but could be other like gmd:extent)
• transformation: eg. gmd:descriptiveKeywords could be added as XLinks, gco:CharacterString, gmx:Anchor

The configuration could be made on a per profile basis and the type of transformation will be available as a choice in the thesaurus selection popup (instead of having the xlink or not only option as currently).

The configuration would look like this:

<!-- All thesaurus for gmd:descriptiveKeywords -->
<registerAssociation registerId="local://thesaurus/*" element="gmd:descriptiveKeywords"/>

<!-- 3 conversions from SKOS to ISO -->
<!-- Add keyword as ISO19139 fragments -->
<registerTransformation element="gmd:descriptiveKeywords" xslTpl='skos2gmd_keywords'/>
<!-- Add keyword as ISO19139 fragments using gmx:Anchor -->
<registerTransformation element="gmd:descriptiveKeywords" xslTpl='skos2gmd_keywords_with_anchor'/>
<!-- Add keyword using an Xlink -->
<registerTransformation element="gmd:descriptiveKeywords" xslTpl='skos2gmd_keywords_with_xlink'/>

I'll write a draft proposal on it this month probably.

For 2.8.x, it's maybe better to keep gco:CharacterString by default ? as gmx:Anchor is probably not so well known for the general user.

[mcoudert]

Yep Simon and François, I fully understand the need or the use of the gmx:Anchor for keywords but my concern is more focused on coming 2.8 version where defaults gmx:Anchor elements break the computing extent from keywords process. Can we update the process stylesheet to support default gmx:Anchor or maybe can we set back gco:CharacterString as default element when creating keywords for the 2.8.x branch? Any thoughts...

[simonp]

I'll happily update the process stylesheet to handle both (don't think this is a big task). Also, for the time being (until we get a per profile config as described above) maybe we could config this as a global option - default is the kind of stupid old gco:Char thing but if config is set then Anchors are used. Certainly critical for Anchors to be supported for use cases here where we sometimes have > 10 thesauri in use....

[fxp]

Here is a mechanism which could handle CharacterString, Anchor and XLink addition mode using a widget in the editor instead of the popup. See  http://www.youtube.com/watch?v=prSRnnUmyDA

Feedback welcomed.

This change could be added to 2.9.x I think.