Chart of event histories

Author: nalabjp

app/controllers/static_pages_controller.rb

@@ -34,6 +34,7 @@ def stats
     end
 
     @annual_dojos_chart = HighChartsBuilder.build_annual_dojos
+    @annual_event_histories_chart = HighChartsBuilder.build_annual_event_histories
   end
 
   def letsencrypt

app/models/high_charts_builder.rb

@@ -18,6 +18,24 @@ def build_annual_dojos
       end
     end
 
+    def build_annual_event_histories
+      source = EventHistory.where('evented_at < ?', Time.current.beginning_of_year).group("DATE_TRUNC('year', evented_at)").count
+      data = annual_chart_data_from(source)
+
+      LazyHighCharts::HighChart.new('graph') do |f|
+        f.title(text: '開催回数の推移')
+        f.xAxis(categories: data[:years])
+        f.series(type: 'column', name: '開催回数', yAxis: 0, data: data[:increase_nums])
+        f.series(type: 'line', name: '累積合計', yAxis: 1, data: data[:cumulative_sums])
+        f.yAxis [
+          { title: { text: '開催回数' } },
+          { title: { text: '累積合計' }, opposite: true }
+        ]
+        f.chart(width: 600)
+        f.colors(["#8085e9", "#f7a35c"])
+      end
+    end
+
     private
 
     def annual_chart_data_from(source)

app/views/static_pages/stats.html.haml

@@ -61,6 +61,7 @@
               %td= @participants[year]
             %td= @participants.values.inject(:+)
       = high_chart("annual_dojos", @annual_dojos_chart)
+      = high_chart("annual_event_histories", @annual_event_histories_chart)
 
     %h3 関連リンク
     %ul{:style => "list-style: none; margin-left: -40px;"}