Parse MODS dates to EDM

[mark-dce]

In order to provide sufficient flexibility to express exact and inexact dates, use the Europeana Data Model Timespan class. Use the 'beginning_is_qualified_by" and "ending_is_qualified_by" predicates to identify

Store the machine readable key date in extendedDate format in DC:date Store the EDM encoded date in the appropriate predicate as follows

MODS Input	RDF Predicate	Notes
originInfo/dateCreated	RDF::DC.created	points to edm:TimeSpan
originInfo/dateIssued	RDF::DC.issued	points to edm:TimeSpan
originInfo/dateModified	RDF::DC.modified	points to edm:TimeSpan, no sample data
originInfo/copyrightDate	RDF::DC.dateCopyrighted	points to edm:TimeSpan
originInfo/dateValid	RDF::DC.valid	points to edm:TimeSpan, no sample data,
N/A	RDF::DC.dateAccepted	implement to support GUI input, no sample data (skipped)
N/A	RDF::DC.dateSubmitted	implement to support GUI input, no sample data (skipped)

If the source MODS record has more than one node per date type (created, issued, accepted, copyrighted, submitted), duplicate the respective predicates and build multiple graph nodes.

If the source MODS record has a text node, map it to a skos:prefLabel element

If the source MODS has point="start" map to edm:begin, if the source MODS has a point="end" map to edm:end. If the source MODS does not specify a point, map the date to edm:begin and leave edm:end blank

If the source MODS record has a date qualifier(s), map the date qualifier(s) to cdm:P79F.beginning_is_qualified_by (begin) and cdm:P80F.end_is_qualified_by (end) - expected values are ['approximate', 'inferred', 'questionable']

Ignore key date and use the following algorithm in #153 to determine sort and faceting dates.

EXAMPLE MAPPINGS

EXAMPLE 1

<mods:dateCreated encoding="w3cdtf" keyDate="yes">1984-11-15</mods:dateCreated>

maps to RDF

<objectURI> <DC.created> <dateOb/jaf87d66a>
<dateOb/jaf87d66a> <edm:begin> "1984-11-15"

---

EXAMPLE 2

<mods:dateIssued encoding="w3cdtf" keyDate="yes">1936</mods:dateIssued>

maps to RDF

<objectURI> <DC.issued> <dateOb/f78823ed1>
<dateOb/f78823ed1> <edm:begin> "1984-11-15"

---

EXAMPLE 3

<mods:dateOther keyDate="yes">Unknown</mods:dateOther>

maps to RDF

<objectURI> <DC.created> <dateOb/f78823ed1>
<dateOb/f78823ed1> <skos:prefLable> "Unknown"

---

EXAMPLE 4

<mods:dateCreated>circa 1910s</mods:dateCreated>
<mods:dateCreated encoding="w3cdtf" point="start" qualifier="approximate" keyDate="yes">1910</mods:dateCreated>
<mods:dateCreated encoding="w3cdtf" point="end" qualifier="approximate">1919</mods:dateCreated>

maps to RDF

<objectURI> <DC.issued> <dateOb/aa8845670>
<dateOb/aa8845670> <edm:begin> "1910"
<dateOb/aa8845670> <edm:end> "1919"
<dateOb/aa8845670> <crm:P79F.beginning_is_qualified_by> "approximate"
<dateOb/aa8845670> <crm:P80F.end_is_qualified_by> "approximate"
<dateOb/aa8845670> <skos:prefLable> "circa 1910s"

REFERENCES: EDM Timespan (narrative): http://labs.europeana.eu/api/record/#edm-timespan EDM Timespan (definition): https://github.com/europeana/corelib/wiki/EDMObjectTemplatesProviders#edmTimespan EDM Timespan (example - search for edm:TimeSpan): http://pro.europeana.eu/files/Europeana_Professional/Share_your_data/Technical_requirements/EDM_Documentation/EDM_Mapping_Guidelines_v2.2.pdf Ruby RDF DC vocab: https://github.com/ruby-rdf/rdf/blob/develop/lib/rdf/vocab/dc.rb HYDRA RDF MODS vocab: https://github.com/projecthydra-labs/rdf-vocab/blob/master/lib/rdf-vocab/vocab/mods.rb

[mark-dce]

Blocked until #150 is completed

[jcoyne]

Unblocked. I believe this is all done except copyrightDate, dateValid and dateModified. DC.date is being used for mods:dateOther, so we can't use that for a keyDate. I don't believe there is any reason we need to persist the keyDate.

[mark-dce]

Agreed - we do not need to persist keyDate - I was trying to express that by saying

Ignore key date and use the following algorithm in #153 to determine sort and faceting dates.

The third example was meant to speak to the idea of "unknown" dates being mapped to DC.created with a timeSpan prefLabel. keyDate was thrown in specifically to show that it's being disregarded:

<mods:dateOther keyDate="yes">Unknown</mods:dateOther>