Use polymorphic relationship for sidecars <=> documents

app/models/concerns/spotlight/solr_document.rb

@@ -11,7 +11,7 @@ module SolrDocument
       extend ActsAsTaggableOn::Taggable
 
       acts_as_taggable
-      has_many :sidecars, class_name: 'Spotlight::SolrDocumentSidecar'
+      has_many :sidecars, class_name: 'Spotlight::SolrDocumentSidecar', as: :document
 
       before_save :save_owned_tags
       after_save :reindex

app/models/spotlight/solr_document_sidecar.rb

@@ -1,13 +1,13 @@
 module Spotlight
   class SolrDocumentSidecar < ActiveRecord::Base
     belongs_to :exhibit
-    belongs_to :solr_document
+    belongs_to :document, polymorphic: true
     serialize :data, Hash
 
     delegate :has_key?, to: :data
 
     def to_solr
-      { blacklight_config.solr_document_model.unique_key.to_sym => solr_document_id, visibility_field => public? }.merge(data_to_solr)
+      { document.class.unique_key.to_sym => document.id, visibility_field => public? }.merge(data_to_solr)
     end
 
     def private!
@@ -18,6 +18,19 @@ def public!
       update public: true
     end
 
+    # Roll our own polymorphism because our documents are not AREL-able
+    def document
+      document_type.new document_type.unique_key => document_id
+    end
+
+    def document_type
+      (super.constantize if defined?(super)) || default_document_type
+    end
+
+    def default_document_type
+      SolrDocument
+    end
+
     protected
 
     def visibility_field

app/serializers/spotlight/exhibit_export_serializer.rb

@@ -21,7 +21,8 @@ class PageExportSerializer  < Spotlight::ExportSerializer(Spotlight::Page)
   class SolrDocumentSerializer < Spotlight::ExportSerializer(Spotlight::SolrDocumentSidecar)
     def filter keys
       keys = super
-      keys += [:solr_document_id]
+      keys += [:document_id]
+      keys += [:document_type]
     end
   end
 

db/migrate/20150217111511_add_polymorphic_document_to_sidecars.rb

@@ -0,0 +1,26 @@
+class AddPolymorphicDocumentToSidecars < ActiveRecord::Migration
+  def change
+    add_column :spotlight_solr_document_sidecars, :document_id, :string
+    add_column :spotlight_solr_document_sidecars, :document_type, :string
+
+    remove_column :spotlight_solr_document_sidecars, :solr_document_id
+
+    reversible do |dir|
+      dir.up do
+        Spotlight::SolrDocumentSidecar.find_each do |e|
+          e.document = SolrDocument.new(id: e.solr_document_id)
+          e.save!
+        end
+      end
+
+      dir.down do
+        Spotlight::SolrDocumentSidecar.find_each do |e|
+          e.solr_document_id = e.document_id
+          e.save!
+        end
+      end
+    end
+
+    add_index :bookmarks, [:document_type, :document_id]
+  end
+end

spec/models/solr_document_spec.rb

@@ -57,7 +57,7 @@
 
   describe "#to_solr" do
     before do
-      Spotlight::SolrDocumentSidecar.create! solr_document: subject, exhibit: exhibit,
+      Spotlight::SolrDocumentSidecar.create! document: subject, exhibit: exhibit,
         data: {'a_tesim' => 1, 'b_tesim' => 2, 'c_tesim' => 3 }
     end
 

spec/models/spotlight/resources/csv_spec.rb

@@ -90,10 +90,10 @@
 
     it "should create sidecar files for custom fields" do
       expect { subject.save! }.to change { Spotlight::SolrDocumentSidecar.count }.by(2)
-      row = subject.exhibit.solr_document_sidecars.where(solr_document_id: "1").first
+      row = subject.exhibit.solr_document_sidecars.where(document_id: "1").first
       expect(row.public).to be_truthy
       expect(row.data[custom_field.field]).to eq "x"
-      row = subject.exhibit.solr_document_sidecars.where(solr_document_id: "2").first
+      row = subject.exhibit.solr_document_sidecars.where(document_id: "2").first
       expect(row.public).to be_falsey
       expect(row.data[custom_field.field]).to eq "w"
     end

spec/models/spotlight/solr_document_sidecar_spec.rb

@@ -4,7 +4,7 @@
   let(:exhibit) { FactoryGirl.create(:exhibit) }
   before do
     allow(subject).to receive_messages exhibit: exhibit
-    allow(subject).to receive_messages solr_document_id: 'doc_id'
+    allow(subject).to receive_messages document: SolrDocument.new(id: 'doc_id')
   end
 
   describe "#to_solr" do

spec/serializers/spotlight/exhibit_export_serializer_spec.rb

@@ -48,11 +48,11 @@
   end
 
   it "should have solr document sidecars" do
-    source_exhibit.solr_document_sidecars.create! solr_document_id: 1, public: false
+    source_exhibit.solr_document_sidecars.create! document: SolrDocument.new(id: 1), public: false
     expect(subject["solr_document_sidecars_attributes"]).to have_at_least(1).item
     expect(subject["solr_document_sidecars_attributes"]).to have(source_exhibit.solr_document_sidecars.count).items
 
-    expect(subject["solr_document_sidecars_attributes"].first).to include('solr_document_id', 'public')
+    expect(subject["solr_document_sidecars_attributes"].first).to include('document_id', 'public')
     expect(subject["solr_document_sidecars_attributes"].first).to_not include 'id'
   end