Add a second argument to #document_partial_name for the current kind …

…of partial we're rendering

This allows downstream implementors to override the calculated
 #document_partial_name on a per-partial basis. E.g. if you had a
heterogeneous index with some records with MODS and MARC data, you could
choose the appropriate rendering format for those records independent of
the regular format.

app/helpers/blacklight/blacklight_helper_behavior.rb

@@ -428,19 +428,25 @@ def document_index_path_templates
 
   ##
   # Return a normalized partial name for rendering a single document
-  # 
+  #
   # @param [SolrDocument]
+  # @param [Symbol] base name for the partial
   # @return [String]
-  def document_partial_name(document)
-    display_type = document[blacklight_config.view_config(:show).display_type_field]
+  def document_partial_name(document, base_name = nil)
+    view_config = blacklight_config.view_config(:show)
+
+    display_type = if base_name and view_config.has_key? :"#{base_name}_display_type_field"
+      document[view_config[:"#{base_name}_display_type_field"]]
+    end
+
+    display_type ||= document[view_config.display_type_field]
 
-    return 'default' unless display_type
-    display_type = display_type.join(" ") if display_type.respond_to?(:join)
+    display_type ||= 'default'
 
     # .to_s is necessary otherwise the default return value is not always a string
     # using "_" as sep. to more closely follow the views file naming conventions
     # parameterize uses "-" as the default sep. which throws errors
-    "#{display_type.gsub("-"," ")}".parameterize("_").to_s
+    Array(display_type).join(" ").gsub("-","_").parameterize("_")
   end
 
   ##
@@ -466,7 +472,7 @@ def render_document_partials(doc, partials = [], locals ={})
   # @param [String] base name for the partial
   # @param [Hash] locales to pass through to the partials
   def render_document_partial(doc, base_name, locals = {})
-    format = document_partial_name(doc)
+    format = document_partial_name(doc, base_name)
 
     document_partial_path_templates.each do |str|
       # XXX rather than handling this logic through exceptions, maybe there's a Rails internals method

spec/helpers/blacklight_helper_spec.rb

@@ -445,4 +445,51 @@ def mock_document_app_helper_url *args
       expect(helper.should_show_spellcheck_suggestions? response).to be_false
     end
   end
+
+  describe "#document_partial_name" do
+    let(:blacklight_config) { Blacklight::Configuration.new }
+
+    before do
+      helper.stub(blacklight_config: blacklight_config)
+    end
+
+    context "with a solr document with empty fields" do
+      let(:document) { SolrDocument.new }
+      it "should be the default value" do
+        expect(helper.document_partial_name(document)).to eq 'default'
+      end
+    end
+
+    context "with a solr document with the display type field set" do
+      let(:document) { SolrDocument.new 'my_field' => 'xyz'}
+
+      before do
+        blacklight_config.show.display_type_field = 'my_field'
+      end
+
+      it "should use the value in the configured display type field" do
+        expect(helper.document_partial_name(document)).to eq 'xyz'
+      end
+
+      it "should use the value in the configured display type field if the action-specific field is empty" do
+        expect(helper.document_partial_name(document, :some_action)).to eq 'xyz'
+      end
+    end
+
+    context "with a solr doucment with an action-specific field set" do
+
+      let(:document) { SolrDocument.new 'my_field' => 'xyz', 'other_field' => 'abc' }
+
+      before do
+        blacklight_config.show.media_display_type_field = 'my_field'
+        blacklight_config.show.metadata_display_type_field = 'other_field'
+      end
+
+      it "should use the value in the action-specific fields" do
+        expect(helper.document_partial_name(document, :media)).to eq 'xyz'
+        expect(helper.document_partial_name(document, :metadata)).to eq 'abc'
+      end
+
+    end
+  end
 end