add logic to toggle reducer keys based off user input

app/controllers/reducers_controller.rb

@@ -46,6 +46,8 @@ def create
       filters['extractor_keys'] = JSON.parse(filters['extractor_keys'])
     end
 
+    reset_config_reducer_keys(new_params)
+
     @reducer = reducer_class.new(new_params)
 
     respond_to do |format|
@@ -72,6 +74,8 @@ def update
       filters['extractor_keys'] = JSON.parse(filters['extractor_keys'])
     end
 
+    reset_config_reducer_keys(params)
+
     @reducer.update(params)
 
     respond_to do |format|
@@ -122,6 +126,8 @@ def reducer_params(klass)
     params.require(:reducer).permit(
       :key,
       :topic,
+      :user_reducer_keys,
+      :subject_reducer_keys,
       *klass.configuration_fields.keys,
       filters: {},
       grouping: {},
@@ -131,4 +137,15 @@ def reducer_params(klass)
   def record_not_valid(exception)
     render json: { error: exception.message }, status: 422
   end
+
+  def reset_config_reducer_keys(param_object)
+    if param_object[:topic] == 'reduce_by_subject'
+      param_object[:subject_reducer_keys] = nil
+    elsif param_object[:topic] == 'reduce_by_user'
+      param_object[:user_reducer_keys] = nil
+    else
+      param_object[:subject_reducer_keys] = nil
+      param_object[:user_reducer_keys] = nil
+    end
+  end
 end

app/views/reducers/_form.html.erb

@@ -15,6 +15,15 @@
 
   <%= f.input :reducible_type, :as => :hidden %>
 
+  <div id='user_reducer_keys'>
+    <%= f.input :user_reducer_keys%>
+  </div>
+
+
+  <div id='subject_reducer_keys'>
+    <%= f.input :subject_reducer_keys%>
+  </div>
+
   <div class="panel panel-info">
     <div class="panel-heading"><a role="button" data-toggle="collapse" href="#groupingInputs" aria-expanded="false" aria-controls="groupingInputs">Grouping <span class="caret"></span></a></div>
     <div class="panel-body collapse" id="groupingInputs">
@@ -50,3 +59,25 @@
     <%= link_to 'Back', project_path(@reducible, anchor: 'reducers'), class: 'btn btn-default' %>
   <% end %>
 <% end %>
+
+<script type="text/javascript">
+  function toggle_reducer_keys_inputs(topic) {
+    if (topic.includes('subject')){
+      $('#subject_reducer_keys').hide()
+      $('#user_reducer_keys').show()
+    } else {
+      $('#subject_reducer_keys').show()
+      $('#user_reducer_keys').hide()
+    }
+  }
+
+  $(function() {
+    var reducer_topic = $('#reducer_topic').val();
+    toggle_reducer_keys_inputs(reducer_topic)
+  });
+
+  $('#reducer_topic').on('change', function(event){
+    var reducer_topic = event.target.value;
+    toggle_reducer_keys_inputs(reducer_topic)
+  })
+</script>

spec/controllers/reducers_controller_spec.rb

@@ -147,6 +147,44 @@
                               reducer: {key: nil, type: 'external'}}
         expect(response.status).to eq(200)
       end
+
+      context 'when topic is reduce_by_subject' do
+        it 'sets subject_reducer_keys to nil' do
+          put :update, params: {
+            workflow_id: workflow.id,
+            id: reducer.id,
+            reducer: {
+              url: 'https://example.org/2',
+              user_reducer_keys: 'user_reducer_keys_value',
+              subject_reducer_keys: 'subject_reducer_keys',
+              topic: 'reduce_by_subject'
+            }
+          }
+
+          reducer.reload
+          expect(reducer.subject_reducer_keys).to be_nil
+          expect(reducer.user_reducer_keys).to eq('user_reducer_keys_value')
+        end
+      end
+
+      context 'when topic is not reduce_by_subject' do
+        it 'sets user_reducer_keys to nil' do
+          put :update, params: {
+            workflow_id: workflow.id,
+            id: reducer.id,
+            reducer: {
+              url: 'https://example.org/2',
+              user_reducer_keys: 'user_reducer_keys_value',
+              subject_reducer_keys: 'subject_reducer_keys_value',
+              topic: 'reduce_by_user'
+            }
+          }
+
+          reducer.reload
+          expect(reducer.subject_reducer_keys).to eq('subject_reducer_keys_value')
+          expect(reducer.user_reducer_keys).to be_nil
+        end
+      end
     end
   end
 end