[SIS-110] Add some intelligence in metadata implementation

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.3
• Component/s: Metadata
• Assignee: Unassigned
• Reporter: Martin Desruisseaux
• Created: 03/Jul/13 13:42
• Updated: 02/Sep/14 09:41

Description

ISO 19115 seems to have some redundancies in metadata information. For example:

• Identification.pointOfContact ↔ Identification.citation.citedResponsibleParty (collection of ResponsibleParty): the former could be defined as a subset of the later where the ResponsibleParty.role attribute is set to Role.POINT_OF_CONTACT.
• Metadata.contact ↔ Metadata.identificationInfo.pointOfContact (collection of ResponsibleParty): the former is the contact responsible for the metadata, while the later is the contact responsible for the resource described by the metadata. However in practice this is often the same contact.
• GeographicBoundingBox ↔ BoundingPolygon: the former could be inferred from the later.
• Georectified.checkPointAvailability ↔ (Georectified.checkPointDescription, Georectified.checkPoint): the former could be set to true if any of the later attribute is non-null. There is many other fooAvailability attribute like that one - all of them may be candidate to such automatic inference.
• OnlineResource.getLinkage(): could be inferred from getDataSetUri().
• OnlineResource.getProtocol(): could be inferred from the scheme part of getLinkage().
• StandardOrderProcess.getOrderOptionType() could be inferred from getOrderOptions().getRecordType().
• Adding a Source to ProcessStep.sources could automatically add the ProcessStep to Source.processSteps by weak reference, and conversely. A similar idea may apply to Platform and Instrument.
• Metadata.identificationInfo.spatialResolutions seems to be synonymous of metadata.spatialRepresentationInfo.axisDimensionProperties.resolution.
• Distribution.formats may be inferred by the union of all contained DigitalTransferOptions.formats.
• Metadata.locale may need to contain all locales used by every InternationalString instances in the metadata tree. This is needed since the locale attribute in <gml:LocalizedCharacterString> is a reference to a locale defined in <PT_Locale> (SIS-137).

As an optional mechanism

We could provide some optional mechanism (to be enabled only if desired) where, if a value was not explicitly given for some attributes, a default value is automatically inferred from other attribute. For example:

• If no value was explicitly given to Metadata.contact, returns Metadata.identificationInfo.pointOfContact.
• If no value was explicitly given to Metadata.identificationInfo.pointOfContact, returns a filtered list of Metadata.identificationInfo.citation.citedResponsibleParty where role = POINT_OF_CONTACT.

Note the cascading of the above two inference mechanisms.

Impact on other code

If the Metadata.pointOfContact property become automatically calculated, then we should remove the duplication done in the NetCDF metadata reader.

Issue Links

• is depended upon by: SIS-137 <gmd:LocalisedCharacterString> locale shall be a URI