Extract a citation component

app/components/blacklight/document/citation_component.html.erb

@@ -0,0 +1,9 @@
+<div>
+  <h1 class="modal-title"><%= title %></h1>
+
+  <%= @formats.each do |i18n_key, citation_method| %>
+    <h2><%= t(i18n_key) %></h2>
+    <%= @document.send(citation_method).html_safe %>
+    <% unless @formats.keys.last === i18n_key %><br/><br/><% end %>
+  <% end %>
+</div>

app/components/blacklight/document/citation_component.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Blacklight
+  module Document
+    class CitationComponent < ::ViewComponent::Base
+      DEFAULT_FORMATS = {
+        'blacklight.citation.mla': :export_as_mla_citation_txt,
+        'blacklight.citation.apa': :export_as_apa_citation_txt,
+        'blacklight.citation.chicago': :export_as_chicago_citation_txt
+      }.freeze
+
+      with_collection_parameter :document
+
+      def initialize(document:, formats: DEFAULT_FORMATS)
+        @document = document
+        @formats = formats.select { |_k, v| @document.respond_to?(v) }
+      end
+
+      def title
+        @view_context.document_heading(@document)
+      end
+    end
+  end
+end

app/views/catalog/_citation.html.erb

@@ -1,22 +1,5 @@
 <%= render Blacklight::System::ModalComponent.new do |component| %>
   <% component.with(:title, t('blacklight.tools.citation')) %>
 
-  <% @documents&.each do |document| %>
-    <h1 class="modal-title"><%= document_heading(document) %></h1>
-
-    <% if document.respond_to?(:export_as_mla_citation_txt) %>
-      <h2><%= t('blacklight.citation.mla') %></h2>
-      <%= document.send(:export_as_mla_citation_txt).html_safe %><br/><br/>
-    <% end %>
-
-    <% if document.respond_to?(:export_as_apa_citation_txt) %>
-      <h2><%= t('blacklight.citation.apa') %></h2>
-      <%= document.send(:export_as_apa_citation_txt).html_safe %><br/><br/>
-    <% end %>
-
-    <% if document.respond_to?(:export_as_chicago_citation_txt) %>
-      <h2><%= t('blacklight.citation.chicago') %></h2>
-      <%= document.send(:export_as_chicago_citation_txt).html_safe %>
-    <% end %>
-  <% end %>
+  <%= render Blacklight::Document::CitationComponent.with_collection(@documents) if @documents.present? %>
 <% end %>