Expand available filters, give applications the ability to filter and order via ENV

README.md

@@ -51,6 +51,14 @@ change as part of the work.
 
 - `ABOUT_APP`: If populated, an 'about' partial containing the contents of this variable will render on 
 `basic_search#index`.
+- `ACTIVE_FILTERS`: If populated, this list of strings defines which filters are shown to the user, and the order in which they appear. Values are case sensitive, and must match those used in the TIMDEX GraphQL query. Extraneous values will be ignored. If not populated, all filters will be shown.
+- `FILTER_CONTENT_TYPE`: The name to use instead of "Content type" for that filter / aggregation.
+- `FILTER_CONTRIBUTOR`: The name to use instead of "Contributor" for that filter / aggregation.
+- `FILTER_FORMAT`: The name to use instead of "Format" for that filter / aggregation.
+- `FILTER_LANGUAGE`: The name to use instead of "Language" for that filter / aggregation.
+- `FILTER_LITERARY_FORM`: The name to use instead of "Literary form" for that filter / aggregation.
+- `FILTER_SOURCE`: The name to use instead of "Source" for that filter / aggregation.
+- `FILTER_SUBJECT`: The name to use instead of "Subject" for that filter / aggregation.
 - `GDT`: Enables features related to geospatial data discovery. Setting this variable with any value will trigger GDT
 mode (e.g., `GDT=false` will still enable GDT features). Note that this is currently intended _only_ for the GDT app and
 may have unexpected consequences if applied to other TIMDEX UI apps.

app/controllers/search_controller.rb

@@ -25,6 +25,10 @@ def results
 
   private
 
+  def active_filters
+    ENV.fetch('ACTIVE_FILTERS', '').split(',').map(&:strip)
+  end
+
   def extract_errors(response)
     response&.errors&.details&.to_h&.dig('data')
   end
@@ -33,17 +37,27 @@ def extract_filters(response)
     aggs = response&.data&.search&.to_h&.dig('aggregations')
     return if aggs.blank?
 
+    aggs = reorder_filters(aggs, active_filters) unless active_filters.blank?
+
     # We use aggregations to determine which terms can be filtered. However, agg names do not include 'filter', whereas
     # our filter fields do (e.g., 'source' vs 'sourceFilter'). Because of this mismatch, we need to modify the
     # aggregation key names before collecting them as filters, so that when a filter is applied, it searches the
     # correct field name.
-    aggs.select { |_, agg_values| agg_values.present? }.transform_keys { |key| (key.dup << 'Filter').to_sym }
+    aggs
+      .select { |_, agg_values| agg_values.present? }
+      .transform_keys { |key| (key.dup << 'Filter').to_sym }
   end
 
   def extract_results(response)
     response&.data&.search&.to_h&.dig('records')
   end
 
+  def reorder_filters(aggs, active_filters)
+    aggs
+      .select { |key, _| active_filters.include?(key) }
+      .sort_by { |key, _| active_filters.index(key) }.to_h
+  end
+
   def validate_q!
     return if params[:advanced]&.strip.present?
     return if params[:q]&.strip.present?

app/helpers/filter_helper.rb

@@ -21,8 +21,13 @@ def add_filter(query, filter, term)
 
   def nice_labels
     {
-      contentTypeFilter: 'Content type',
-      sourceFilter: 'Source'
+      contentTypeFilter: ENV.fetch('FILTER_CONTENT_TYPE', 'Content type'),
+      contributorsFilter: ENV.fetch('FILTER_CONTRIBUTOR', 'Contributor'),
+      formatFilter: ENV.fetch('FILTER_FORMAT', 'Format'),
+      languagesFilter: ENV.fetch('FILTER_LANGUAGE', 'Language'),
+      literaryFormFilter: ENV.fetch('FILTER_LITERARY_FORM', 'Literary form'),
+      sourceFilter: ENV.fetch('FILTER_SOURCE', 'Source'),
+      subjectsFilter: ENV.fetch('FILTER_SUBJECT', 'Subject')
     }
   end
 

app/models/timdex_search.rb

@@ -60,10 +60,30 @@ class TimdexSearch < TimdexBase
             key
             docCount
           }
+          contributors {
+            key
+            docCount
+          }
+          format {
+            key
+            docCount
+          }
+          languages {
+            key
+            docCount
+          }
+          literaryForm {
+            key
+            docCount
+          }
           source {
             key
             docCount
           }
+          subjects {
+            key
+            docCount
+          }
         }
       }
     }

test/controllers/search_controller_test.rb

@@ -417,4 +417,42 @@ def source_filter_count(controller)
       assert(source_filter_count(@controller) == 2)
     end
   end
+
+  test 'applications can customize the displayed filters via ENV' do
+    VCR.use_cassette('data basic controller',
+                     allow_playback_repeats: true,
+                     match_requests_on: %i[method uri body]) do
+      # Our standard test ENV does not define ACTIVE_FILTERS, but this confirms
+      # the behavior when it is not defined.
+      ClimateControl.modify ACTIVE_FILTERS: '' do
+        get '/results?q=data'
+        assert_response :success
+        assert_select '#filters .category .filter-label', { minimum: 1 }
+      end
+
+      # Ask for a single filter, get that filter.
+      ClimateControl.modify ACTIVE_FILTERS: 'subjects' do
+        get '/results?q=data'
+        assert_response :success
+        assert_select '#filters .category .filter-label', { count: 1 }
+        assert_select '#filters .category:first-of-type .filter-label', 'Subject'
+      end
+
+      # The order of the terms matter, so now Format should be first.
+      ClimateControl.modify ACTIVE_FILTERS: 'format, contentType, source' do
+        get '/results?q=data'
+        assert_response :success
+        assert_select '#filters .category .filter-label', { count: 3 }
+        assert_select '#filters .category:first-of-type .filter-label', 'Format'
+      end
+
+      # Including extra values does not affect anything - "nonsense" is extraneous.
+      ClimateControl.modify ACTIVE_FILTERS: 'contentType, nonsense, source' do
+        get '/results?q=data'
+        assert_response :success
+        assert_select '#filters .category .filter-label', { count: 2 }
+        assert_select '#filters .category:first-of-type .filter-label', 'Content type'
+      end
+    end
+  end
 end

test/helpers/filter_helper_test.rb

@@ -67,6 +67,19 @@ class FilterHelperTest < ActionView::TestCase
     assert_nil nice_labels[needle]
   end
 
+  test 'nice_labels will use a value from ENV instead of the default if provided' do
+    label = 'Content type'
+    ClimateControl.modify FILTER_CONTENT_TYPE: nil do
+      needle = :contentTypeFilter
+      assert_equal label, nice_labels[needle]
+    end
+    label = 'Custom label'
+    ClimateControl.modify FILTER_CONTENT_TYPE: label do
+      needle = :contentTypeFilter
+      assert_equal label, nice_labels[needle]
+    end
+  end
+
   test 'remove_filter will remove a specific filter parameter from a search URL' do
     original_query = {
       page: 1,