MDTranslator ISO19115-2 to DCATUS: Temporal

[Jin-Sun-tts]

User Story

In order to transform ISO19115-2 documents into DCATUS using mdtranslator, datagov wants to add processing for Temporal

Acceptance Criteria

• [ ] GIVEN the DCATUS Temporal field \ AND how the DCATUS writer expects to find the data within the internal metadata object WHEN the associated ISO19115-2 reader ruby modules are created THEN Temporal should be transformed from ISO19115-2 to DCATUS

Background

• related to #4862
• We process 291017 ISO19115-2 datasets. We want all our datasets to be in DCATUS.
• This reader is not intended to be feature complete according to the ISO19115-2 standard. All we're looking to read is as much as the DCATUS writer expects.
• ISO19115-3 development workflow

Security Considerations (required)

None

Sketch

• field mapping relationship ISO19115-2 -> MDJSON -> DCATUS
  • .//gmd:MD_DataIdentification//gmd:extent//gmd:EX_Extent//gmd:temporalElement//gmd:extent//gml:TimePeriod
  • intObj[:metadata][:metadataInfo][:extents][:temporalExtents][:timePeriod]
  • Temporal
• add processing in resourceInfo to read keywords from gmd:MD_DataIdentification
• create a transformation test demonstrating how the value went from the ISO19115-2 document into the DCATUS json
• create a response object message test verifying when required elements are missing

[Jin-Sun-tts]

https://resources.data.gov/resources/podm-field-mapping/

1. gml:TimePeriod //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/ //gmd:temporalElement/gmd:EX_TemporalExtent/gmd:extent/gml:TimePeriod/gml:beginPosition and //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:temporalElement/ //gmd:EX_TemporalExtent/gmd:extent/gml:TimePeriod/gml:endPosition

2. if single date use this field to populate as both start/end date //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:temporalElement/ //gmd:EX_TemporalExtent/gmd:extent/gml:TimeInstant/timePosition

3. if more than two instances of this field exist choose the earliest date value and latest date value to populate the range of dates //gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:temporalElement/ //gmd:EX_TemporalExtent/gmd:extent/gml:TimeInstant/timePosition

[Jin-Sun-tts]

from the dcat_us_temporal writer, it retrieves the temporal information from [:temporalExtents][:timePeriod].

Additionally, since thegmd:temporalElementmay either share the same gmd:extentparent or be separated across multiple gmd:extent elements, the dcat_us_temporal writer has been updated to account for potential multiple extents, ensuring that both geographic and temporal elements are checked across different gmd:extent entries. (reverted this change as we would like to keep the current writer )

[Jin-Sun-tts]

we are not going to modify the dcat_us_temporal writer for now, we modified the test xml file to only have one parent gmd:extent includes both geographicElementandtemporalElement

here is the question:

Multiple instances of gmd:extent can exist. In such cases, the temporalElement may be located under a different parent extent. However, the dcatus_temporal only checks and gets timePeriod from the first extent. How do we handle this situation?