Switch to OCLC Discovery API Citation service

Gemfile

@@ -89,6 +89,7 @@ gem "devise"
 gem "devise-guests"
 gem 'devise-remote-user'
 gem "faraday"
+gem 'oauth2'
 gem "config"
 gem "mods_display", "~> 1.1"
 gem "font-awesome-rails"

Gemfile.lock

@@ -728,6 +728,7 @@ DEPENDENCIES
   mysql2
   newrelic_rpm
   nokogiri (>= 1.7.1)
+  oauth2
   okcomputer
   parslet (~> 2.0)
   puma (~> 6.0)

app/components/citations/citation_component.html.erb

@@ -0,0 +1,12 @@
+<% citations.each do |style, citation| %>
+  <div class="mb-4">
+    <% unless style == 'NULL' %>
+      <h4><%= t("searchworks.citations.styles.#{style}") %></h4>
+    <% end %>
+    <% Array(citation).each do |cite| %>
+      <div class="mb-2">
+        <%= cite %>
+      </div>
+    <% end %>
+  </div>
+<% end %>

app/components/citations/citation_component.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module Citations
+  class CitationComponent < ViewComponent::Base
+    attr_reader :citations
+
+    def initialize(citations:)
+      @citations = citations
+      super()
+    end
+
+    def render?
+      citations.present?
+    end
+  end
+end

app/components/citations/grouped_citation_component.html.erb

@@ -0,0 +1 @@
+<%= render Citations::CitationComponent.new(citations: grouped_citations) %>

app/components/citations/grouped_citation_component.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module Citations
+  class GroupedCitationComponent < ViewComponent::Base
+    attr_reader :citations
+
+    PREFERRED_CITATION_KEY = 'preferred'
+
+    # @param [Array<Hash>] citations in the form of [{ citation_style => citation_text }]
+    def initialize(citations:)
+      @citations = citations
+      super()
+    end
+
+    # @return [Hash] A hash of citations grouped by style in the form of { citation_style => [citation_text] }
+    def grouped_citations
+      citation_styles.index_with { |style| citations.pluck(style).compact }
+    end
+
+    def render?
+      citations.present?
+    end
+
+    private
+
+    def citation_styles
+      keys = citations.map(&:keys).flatten.uniq
+      # It doesn't make sense to display the NULL citation
+      # when grouping citations by style so remove it from the list
+      keys.delete('NULL')
+
+      # If the preferred citation is present, move it to the front of the list
+      # so that it always displays first
+      return keys unless keys.include?(PREFERRED_CITATION_KEY)
+
+      keys.delete(PREFERRED_CITATION_KEY)
+      keys.unshift(PREFERRED_CITATION_KEY)
+    end
+  end
+end

app/components/citations/multiple_citations_component.html.erb

@@ -0,0 +1,13 @@
+<div class="tab-content">
+  <div role="tabpanel" class="tab-pane active" id="all" aria-labelledby="by-title-button">
+    <% @documents.each do |document| %>
+      <h3 class="mt-4 mb-3"><%= helpers.document_presenter(document).heading %></h3>
+      <%= render Citations::CitationComponent.new(citations: citations(document)) %>
+    <% end %>
+  </div>
+  <div role="tabpanel" class="tab-pane" id="biblio" aria-labelledby="by-format-button">
+    <div class="my-3">
+      <%= render Citations::GroupedCitationComponent.new(citations: @documents.map { |doc| citations(doc) }) %>
+    </div>
+  </div>
+</div>

app/components/citations/multiple_citations_component.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module Citations
+  class MultipleCitationsComponent < ViewComponent::Base
+    attr_reader :documents, :oclc_citations
+
+    # @param [Array<SolrDocument>] documents to generate citations for
+    # @param [Hash] oclc_citations in the form of { oclc_number => { citation_style => citation_text } }
+    #               for lookup of pre-fetched OCLC citations
+    def initialize(documents:, oclc_citations:)
+      @documents = documents
+      @oclc_citations = oclc_citations
+      super()
+    end
+
+    # @return [Hash] A hash of citations for each document in the form of { citation_style => [citation_text] }
+    def citations(document)
+      citation_hash = {}
+
+      citation_hash.merge!(document.mods_citations)
+      citation_hash.merge!(document.eds_citations)
+      citation_hash.merge!(oclc_citation(document))
+
+      citation_hash.presence || Citation::NULL_CITATION
+    end
+
+    private
+
+    def oclc_citation(document)
+      return {} if document.oclc_number.blank?
+
+      oclc_citations.fetch(document.oclc_number, {})
+    end
+  end
+end

app/controllers/catalog_controller.rb

@@ -508,6 +508,16 @@ def email
     end
   end
 
+  # Overridden from Blacklight to pre-fetch OCLC citations in bulk
+  # when more than one document's citation is being displayed.
+  def citation
+    @response, @documents = search_service.fetch(Array(params[:id]))
+    return unless @documents.size > 1
+
+    oclc_numbers = @documents.filter_map { |document| document.oclc_number.presence }
+    @oclc_citations = Citations::OclcCitation.new(oclc_numbers:).citations_by_oclc_number
+  end
+
   def stackmap
     params.require(:library) # Sometimes bots are calling this service without providing required parameters. Raise an error in this case.
     render layout: !request.xhr?

app/helpers/catalog_helper.rb

@@ -50,10 +50,6 @@ def link_to_database_search(subject)
     link_to(subject, search_catalog_path(f: { db_az_subject: [subject], SolrDocument::FORMAT_KEY => ['Database'] }))
   end
 
-  def grouped_citations(documents)
-    Citation.grouped_citations(documents.map(&:citations))
-  end
-
   def tech_details(document)
     details = []
     details.push link_to(

app/models/citation.rb

@@ -2,147 +2,77 @@
 
 ###
 # Citation is a simple class that takes a Hash like object (SolrDocument)
-# and returns a hash of citations for the configured formats
+# and returns a hash of citations
 class Citation
-  def initialize(document, formats = [])
+  NULL_CITATION = { 'NULL' => '<p>No citation available for this record</p>'.html_safe }.freeze
+
+  # @param document [SolrDocument] A document to generate citations for
+  def initialize(document)
     @document = document
-    @formats = formats
   end
 
+  # @return [Boolean] Whether or not the document is citable
   def citable?
-    field.present? || citations_from_mods.present? || citations_from_eds.present?
+    show_oclc_citation? || citations_from_mods.present? || citations_from_eds.present?
   end
 
+  # @return [Hash] A hash of all citations for the document
+  #          in the form of { citation_style => [citation_text] }
   def citations
-    return null_citation if return_null_citation?
-    return all_citations if all_formats_requested?
-
-    all_citations.select do |format, _|
-      desired_formats.include?(format)
-    end
+    all_citations.presence || NULL_CITATION
   end
 
-  def api_url
-    "#{base_url}/#{field}?cformat=all&wskey=#{api_key}"
+  # @return [Hash] A hash of MODS citations for the document
+  #          Used when assembling citations for multiple documents
+  #          in the form of { citation_style => [citation_text] }
+  def mods_citations
+    citations_from_mods.presence || {}
   end
 
-  class << self
-    def grouped_citations(all_citations)
-      citations = all_citations.each_with_object({}) do |cites, hash|
-        cites.each do |format, citation|
-          hash[format] ||= []
-          hash[format] << citation
-        end
-      end
-      # Append preferred citations to front of hash
-      citations = {
-        preferred_citation_key => citations[preferred_citation_key]
-      }.merge(citations.except(preferred_citation_key)) if citations[preferred_citation_key]
-      citations
-    end
-
-    def preferred_citation_key
-      'PREFERRED CITATION'
-    end
-
-    # This being a valid test URL is predicated on the fact
-    # that passing no OCLC number to the citations API responds successfully
-    def test_api_url
-      new(SolrDocument.new).api_url
-    end
+  # @return [Hash] A hash of EDS citations for the document
+  #          Used when assembling citations for multiple documents
+  #          in the form of { citation_style => [citation_text] }
+  def eds_citations
+    citations_from_eds.presence || {}
   end
 
   private
 
-  attr_reader :document, :formats
+  attr_reader :document
 
-  def return_null_citation?
-    all_citations.blank? || (field.blank? && all_citations.blank?)
-  end
-
-  def element_is_citation?(element)
-    element.attributes &&
-      element.attributes['class'] &&
-      element.attributes['class'].value =~ /^citation_style_/i
-  end
-
-  def all_formats_requested?
-    desired_formats == ['ALL']
-  end
+  delegate :oclc_number, to: :document
 
   def all_citations
     @all_citations ||= begin
       citation_hash = {}
-      if citations_from_mods.present?
-        citation_hash[self.class.preferred_citation_key] = "<p>#{citations_from_mods}</p>".html_safe
-      end
 
+      citation_hash.merge!(citations_from_mods) if citations_from_mods.present?
       citation_hash.merge!(citations_from_eds) if citations_from_eds.present?
+      citation_hash.merge!(citations_from_oclc) if citations_from_oclc.present?
 
-      citation_hash.merge!(citations_from_oclc_response) if field.present?
       citation_hash
     end
   end
 
-  def citations_from_oclc_response
-    Nokogiri::HTML(response).css('p').each_with_object({}) do |element, hash|
-      next unless element_is_citation?(element)
+  def citations_from_oclc
+    return unless show_oclc_citation?
 
-      element.attributes['class'].value[/^citation_style_(.*)$/i]
-      hash[Regexp.last_match[1].upcase] = element.to_html.html_safe
-    end
+    @citations_from_oclc ||= Citations::OclcCitation.new(oclc_numbers: oclc_number).citations_by_oclc_number.fetch(oclc_number, {})
   end
 
   def citations_from_mods
     return unless document.mods && document.mods.note.present?
 
-    document.mods.note.find do |note|
-      note.label.downcase =~ /preferred citation:?/
-    end.try(:values).try(:join)
+    @citations_from_mods ||= Citations::ModsCitation.new(notes: document.mods.note).all_citations
   end
 
   def citations_from_eds
     return unless document.eds? && document['eds_citation_styles'].present?
 
-    document['eds_citation_styles'].each_with_object({}) do |citation, hash|
-      next unless citation['id'] && citation['data']
-
-      hash[citation['id'].upcase] = citation['data'].html_safe
-    end
-  end
-
-  def response
-    @response ||= begin
-      Faraday.get(api_url).body
-    rescue Faraday::ConnectionFailed, Faraday::TimeoutError => e
-      Rails.logger.warn("HTTP GET for #{api_url} failed with #{e}")
-      ''
-    end
-  end
-
-  def field
-    Array(document[config.DOCUMENT_FIELD]).try(:first)
-  end
-
-  def desired_formats
-    return config.CITATION_FORMATS.map(&:upcase) unless formats.present?
-
-    formats.map(&:upcase)
-  end
-
-  def base_url
-    config.BASE_URL
-  end
-
-  def api_key
-    config.API_KEY
-  end
-
-  def config
-    Settings.OCLC
+    @citations_from_eds ||= Citations::EdsCitation.new(eds_citation_styles: document['eds_citation_styles']).all_citations
   end
 
-  def null_citation
-    { 'NULL' => '<p>No citation available for this record</p>'.html_safe }
+  def show_oclc_citation?
+    Settings.oclc_discovery.citations.enabled && oclc_number.present?
   end
 end

app/models/citations/eds_citation.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+###
+# Returns an EDS citation formatted for use by SearchWorks
+module Citations
+  class EdsCitation
+    CITATION_STYLES = %w[apa chicago harvard mla turabian].freeze
+
+    attr_reader :eds_citation_styles
+
+    # @param eds_citation_styles [Array<Hash>] An array of EDS citations
+    def initialize(eds_citation_styles:)
+      @eds_citation_styles = eds_citation_styles
+    end
+
+    # @return [Hash] A hash with citation styles as keys and citation text as values.
+    def all_citations
+      matching_styles.index_with do |id|
+        eds_citation_styles.select { |style| style.fetch('id', nil) == id }.pick('data')&.html_safe # rubocop:disable Rails/OutputSafety
+      end.compact
+    end
+
+    private
+
+    def matching_styles
+      eds_citation_styles.pluck('id').select { |id| CITATION_STYLES.include?(id) }
+    end
+  end
+end