This somewhat works

I need to introduce Cells

app/controllers/generic_controller.rb

@@ -9,8 +9,15 @@ def index
 
     @model = find_class
     @metrics = @model.where(datetime: (Time.now - @hours.hours)..Time.now)
+
+    if @metrics == []
+      @metrics = @model.first(3)
+    end
+
     @bucketed_metrics = @metrics.group_by { |g| g.datetime.strftime "%Y-%m-%d" }
 
+    @with_year = @metrics.first.datetime.year < Time.now.year
+
     @has_charts = false
   end
 

app/controllers/longterm_controller.rb

@@ -6,7 +6,8 @@ def index
       {
         model: GlycatedHaemoglobin,
         metrics: GlycatedHaemoglobin.all,
-        bucketed_metrics: GlycatedHaemoglobin.all.group_by { |g| g.datetime.strftime "%Y-%m-%d" }
+        bucketed_metrics: GlycatedHaemoglobin.all.group_by { |g| g.datetime.strftime "%Y-%m-%d" },
+        with_year: nil
       },
       {
         model: BloodPressure,

spec/requests/sparse_metrics_spec.rb

@@ -0,0 +1,26 @@
+describe 'GlycatedHaemoglobin' do
+  describe 'Return at least something if the metric is sparse' do
+    let(:user) { create :user }
+
+    before :each do
+      DatabaseCleaner.clean
+    end
+
+    it 'shows the year if the first metric is from last year or even older' do
+      create(:glycated_haemoglobin, datetime: '2015-06-06')
+      Timecop.freeze 2016, 02, 27 do
+        visit glycated_haemoglobins_url(as: user)
+        expect(page).to have_content 'June 6th 2015'
+      end
+    end
+
+    it 'does not show the year if the first metric is from this year' do
+      create(:glycated_haemoglobin, datetime: '2016-01-01')
+      Timecop.freeze 2016, 02, 27 do
+        visit glycated_haemoglobins_url(as: user)
+        expect(page).to have_content 'January 1st'
+        expect(page).to_not have_content 'January 1st 2016'
+      end
+    end
+  end
+end