Support typed EDTF data for the Etd#date field

An `RDF::Literal` subclass for EDTF datatypes is introduced. This supports the
id.loc.gov namespaced datatype for EDTF and can accept any string value as its
lexical value. We test that when a date is set to this type, it is correctly
serialized in the object's `.ttl` view.

Handling is added to `EtdIndexer#generate_solr_document` to ensure edtf dates
are indexed text values (they are also indexed as dates, but we do not consume
them in catalog controller or elsewhere). The correct appearance of typed data
in the show view is tested.

Dates input through the `EtdForm` are cast to the typed literal so they can be
serialized to Fedora with the correct type. We assume any value put into the
"EDTF Date" form field is intended to be interpreted as typed data.

Factories are updated to set an EDTF date on build.

Closes #186.

app/controllers/catalog_controller.rb

@@ -115,7 +115,7 @@ def self.modified_field
     config.add_show_field solr_name("license", :stored_searchable)
 
     # Core show fields
-    config.add_show_field solr_name('date',        :stored_searchable)
+    config.add_show_field solr_name('date', :stored_searchable)
 
     # ETD show fields
     config.add_show_field solr_name('date_label',  :stored_searchable)

app/forms/hyrax/etd_form.rb

@@ -6,5 +6,16 @@ class EtdForm < Hyrax::Forms::WorkForm
     self.single_valued_fields = [:degree, :school, :department, :institution].freeze
     self.model_class = ::Etd
     self.terms += [:degree, :date, :date_label, :department, :institution, :orcid_id, :resource_type, :rights_note, :school]
+
+    ##
+    # Cast `:date` parameters from the form to EDTF.
+    #
+    # We don't care if the dates are valid. `"moomin"` is a perfectly acceptable
+    # EDTF date for our purposes.
+    def self.model_attributes(form_params)
+      result = super
+      result[:date].map! { |date| Mahonia::EdtfLiteral.new(date) }
+      result
+    end
   end
 end

app/indexers/etd_indexer.rb

@@ -22,5 +22,19 @@ class IndexingService < Hyrax::DeepIndexingService
 
     stored_fields.delete(:license)
     stored_fields.delete(:rights_statement)
+
+    ##
+    # Index EDTF dates
+    def generate_solr_document
+      super.tap do |solr_doc|
+        if object.date.any?
+          date_key = Solrizer.solr_name('date')
+
+          solr_doc[date_key] ||= []
+          solr_doc[date_key] +=
+            object.date.select { |date| date.respond_to?(:edtf) }.map(&:edtf)
+        end
+      end
+    end
   end
 end

app/lib/mahonia/edtf_literal.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Mahonia
+  class EdtfLiteral < RDF::Literal
+    DATATYPE = RDF::URI('http://id.loc.gov/datatypes/edtf/EDTF')
+
+    # support ActiveJob serialization
+    include GlobalID::Identification
+
+    def self.find(id)
+      new(id)
+    end
+
+    def initialize(value, **opts)
+      value = EDTF.parse(value) || value
+      @string = value.edtf if value.respond_to? :edtf
+      super
+    end
+
+    def id
+      value
+    end
+  end
+end

spec/factories/etds.rb

@@ -52,7 +52,7 @@
     factory :moomins_thesis do
       title            ['Moomintroll']
       creator          ['Moomin', 'Hemulen']
-      date             ['199?']
+      date             [Mahonia::EdtfLiteral.new('199x')]
       publisher        ['A Publisher']
       date_created     [Date.parse('2016-12-25')]
       date_label       ['Winter in Moomin Valley']

spec/features/create_etd_spec.rb

@@ -43,6 +43,7 @@
       fill_in 'Description', with: etd[:description].first
       # term for license URI set in factory
       select('Creative Commons BY-SA Attribution-ShareAlike 4.0 International', from: 'License')
+      fill_in 'EDTF Date', with: etd[:date].first
       fill_in 'Publisher', with: etd[:publisher].first
       fill_in 'Date Created', with: etd[:date_created].first
       fill_in 'Subject', with: etd[:subject].first
@@ -66,6 +67,10 @@
       # wait until we have a record
       persisted_etd = Etd.where(title: etd[:title].first) while persisted_etd.nil?
 
+      # ensure the EDTF date is typed
+      expect(persisted_etd.first)
+        .to have_attributes(date: contain_exactly(*etd[:date].map(&:object)))
+
       expect(page).to have_content etd[:title].first
       expect(page).to have_content etd[:creator].first
       expect(page).to have_content etd[:keyword].first
@@ -75,6 +80,7 @@
       # license
       expect(page).to have_content 'Creative Commons BY-SA Attribution-ShareAlike 4.0 International'
       expect(page).to have_content etd[:publisher].first
+      expect(page).to have_content etd[:date].first
       expect(page).to have_content etd[:subject].first
       expect(page).to have_content etd[:language].first
       # Identifier sets DOI

spec/features/edit_etd_spec.rb

@@ -43,6 +43,7 @@
       fill_in 'Description', with: etd[:description].first
       # term for license URI set in factory
       select('Creative Commons BY-SA Attribution-ShareAlike 4.0 International', from: 'License')
+      fill_in 'EDTF Date', with: etd[:date].first
       fill_in 'Date Created', with: etd[:date_created].first
       fill_in 'Subject', with: etd[:subject].first
       fill_in 'Language', with: etd[:language].first
@@ -73,6 +74,7 @@
       fill_in 'Description', with: "Edited Description"
       # term for license URI set in factory
       select('Creative Commons BY-SA Attribution-ShareAlike 4.0 International', from: 'License')
+      fill_in 'EDTF Date', with: 'Edited Date'
       fill_in 'Subject', with: "Edited Subject"
       fill_in 'Language', with: "Edited Language"
       fill_in 'Identifier', with: "Edited Identifier"
@@ -105,6 +107,7 @@
       expect(page).to have_content "Edited Keyword"
       expect(page).to have_content "In Copyright"
       expect(page).to have_content "Edited Description"
+      expect(page).to have_content "Edited Date"
       expect(page).to have_content "Edited Subject"
       expect(page).to have_content "Edited Language"
       expect(page).to have_content "Edited Identifier"

spec/indexers/etd_indexer_spec.rb

@@ -5,6 +5,16 @@
   subject(:indexer) { described_class.new(etd) }
   let(:etd)         { FactoryGirl.build(:etd) }
 
+  describe '#generate_solr_document' do
+    let(:dates) { [Mahonia::EdtfLiteral.new('2999?'), '1999'] }
+    let(:etd)   { FactoryGirl.build(:etd, date: dates) }
+
+    it 'indexes EDTF datatypes' do
+      expect(indexer.generate_solr_document)
+        .to include('date_tesim' => contain_exactly('1999', '2999?'))
+    end
+  end
+
   describe '#rdf_service' do
     it 'has facetable fields' do
       expect(indexer.rdf_service.stored_and_facetable_fields)

spec/lib/mahonia/edtf_literal_spec.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+require 'rails_helper'
+
+RSpec.describe Mahonia::EdtfLiteral do
+  subject(:literal) { described_class.new(edtf_str) }
+  let(:edtf_str)    { '199x' }
+
+  it 'has an EDTF datatype' do
+    expect(literal)
+      .to have_attributes(datatype: RDF::URI('http://id.loc.gov/datatypes/edtf/EDTF'))
+  end
+end

spec/presenters/hyrax/etd_presenter_spec.rb

@@ -31,6 +31,10 @@
       expect(presenter.export_as_ttl).to include(*predicates)
     end
 
+    it 'has an ETDF date with datatype' do
+      expect(presenter.export_as_ttl).to include('<http://id.loc.gov/datatypes/edtf/EDTF>')
+    end
+
     context 'with an embargo' do
       let(:etd) { FactoryGirl.create(:embargoed_etd) }
 

spec/views/hyrax/base/_metadata.html.erb_spec.rb

@@ -15,7 +15,7 @@
   it { is_expected.to have_show_field(:creator).with_values(*work.creator).and_label('Creator') }
   # underspecify date values (they aren't necessarily sensible for all Date/DateTime values)
   it { is_expected.to have_show_field(:date_created).with_label('Date created') }
-  it { is_expected.to have_show_field(:date).with_values(*work.date).and_label('EDTF Date') }
+  it { is_expected.to have_show_field(:date).with_values(*work.date.map(&:to_s)).and_label('EDTF Date') }
   it { is_expected.to have_show_field(:date_label).with_values(*work.date_label).and_label('Date label') }
   it { is_expected.to have_show_field(:degree).with_values(*work.degree).and_label('Degree Name') }
   it { is_expected.to have_show_field(:department).with_values(*work.department).and_label('Department') }