Adding Registers to GeoNetwork

Date	2011-10-26
Contact(s)	Simon Pigot
Last edited	2011-10-26T18:25:00
Status	Being discussed, in progress, initial implementation in progress
Assigned to release	2.9.x
Resources	Available
Ticket #	#XYZ

Overview

A register as defined in ISO19135 is a list of items that have been assigned an identifier. ISO19135 has models of a register and describes the roles and procedures necessary for registering an item. An registered item may be any piece of geographic information. For the purposes of this proposal the items in the register will be the codelists or vocabularies associated with a metadata record. This proposal describes:

• the addition of the XML schema implementation of ISO19135 to GeoNetwork as a plugin schema
• how codelists, vocabularies and thesaurii will be implemented as ISO19135 records (registers) in GeoNetwork
• how metadata records in a metadata schema will be linked to these registers

Proposal Type

• Type: GUI Change, Core Change
• App: GeoNetwork
• Module: Harvester, Kernel

Links

• Documents: ISO19135: Geographic information - Procedures for item registration (unfortunately this must be purchased from ISO)
• ISO19135 Plugin Schema Implementation for GeoNetwork: ​http://geonetwork.svn.sourceforge.net/viewvc/geonetwork/schemaPlugins/trunk/iso19135/

Voting History

• Vote not yet proposed.

Motivations

Currently:

• Vocabularies, codelists and thesauri are held in static files external to the GeoNetwork catalog. The process by which items in these registers are modified, updated, superseded or retired are invisible as the formats they are held in do not support capture of this information.
• Metadata records that use items from these registers usually do so by referencing a document that is not in the catalog and cannot be retrieved by searching the catalog (eg. ​http://asdd.ga.gov.au/asdd/profileinfo/anzlic-theme.xml)
• The content of a register is often copied into another format for convenience eg. the ISO19139 codelists in ​http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml are copied into a codelists.xml file and stored in the localized GeoNetwork directory for use by the GeoNetwork editor. This should be modified so that the register content is not copied, only the association between the register and an element is held otherwise recording and propagating changes to register content is too difficult.

The motivation for this proposal is to:

• implement ISO19135 so that register changes and evolution are captured in the ISO19135 register record
• make ISO19135 registers transportable between catalogs through harvesting
• have all GeoNetwork tasks that need a register item access it from the ISO19135 register record
• allow GeoNetwork to manage ISO19135 registers

Proposal

• Implement ISO19135 register models (implemented as a draft XML schema at ​http://www.isotc211.org/2005/grg/register.xsd) as a plugin schema for GeoNetwork
• Develop an XSLT to convert the ISO19139 CT_CodelistCatalog format to ISO19135 register format
• Add ISO19135 register records to ISO metadata schemas and profiles (to be loaded with the schema/profile or regularly harvested into GeoNetwork category 'Registers')
• Develop a registerAssociation.xml file as an alternative to the codelists.xml file currently used in GeoNetwork. Instead of copying the content of the register into the file as is done with codelists.xml, the registerAssociation.xml file will simply hold associations between elements and the uuid of the ISO19135 register record. Example of an element from this file for the iso19139.anzlic metadata schema:

      <registerAssociation registerId="uuid_of_GeoScience_Australia_scopecode_register" element="gmd:MD_ScopeCode"/>
      <registerAssociation registerId="uuid_of_ISO19139_rolecode_codelist_register" element="gmd:CI_RoleCode"/>
      ....
      .... 
  

• GeoNetwork looks up the codelist item in the list of register records associated with the metadata schema of the metadata record being edited.
• Codelist elements in a metadata record would look as follows:

      <gmd:MD_ScopeCode codeListValue="utf8" 
                        codeList="http://geonetwork-site-url/xml_iso19135?uuid={uuid_of_GeoScience_Australia_scopecode_register}" 
                        codeSpace="{identifier_of_codeListValue_in_ISO19135_record}"/>
  

• Develop an XSLT to convert ISO19135 registers to SKOS for use as a thesaurus in GeoNetwork.

Note that register items other than codelists, vocabularies and thesauri could be supported at a later date.

Backwards Compatibility Issues

None - if the ISO19135 register records for a metadata schema don't exist then the code for this proposal won't be used.

New libraries added

None.

Risks

Everything involves some element of risk....

Participants

• Simon Pigot
• Others?