Chart of dojo number

Author: nalabjp

app/controllers/static_pages_controller.rb

@@ -32,6 +32,8 @@ def stats
         EventHistory.where(evented_at:
                      Time.zone.local(year).beginning_of_year..Time.zone.local(year).end_of_year).sum(:participants)
     end
+
+    @annual_dojos_chart = HighChartsBuilder.build_annual_dojos
   end
 
   def letsencrypt

app/models/high_charts_builder.rb

@@ -0,0 +1,36 @@
+class HighChartsBuilder
+  class << self
+    def build_annual_dojos
+      source = Dojo.where('created_at < ?', Time.current.beginning_of_year).group("DATE_TRUNC('year', created_at)").count
+      data = annual_chart_data_from(source)
+
+      LazyHighCharts::HighChart.new('graph') do |f|
+        f.title(text: '全国の道場数の推移')
+        f.xAxis(categories: data[:years])
+        f.series(type: 'column', name: '増加数', 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: '増加数' } },
+          { 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)
+      sorted_list = source.each.with_object({}) {|(k, v), h| h[k.year] = v }.sort
+      years = sorted_list.map(&:first)
+      increase_nums = sorted_list.map(&:last)
+      cumulative_sums = increase_nums.size.times.map {|i| increase_nums[0..i].inject(:+) }
+
+      {
+        years: years,
+        increase_nums: increase_nums,
+        cumulative_sums: cumulative_sums
+      }
+    end
+  end
+end

app/views/static_pages/stats.html.haml

@@ -60,6 +60,7 @@
             - @range.each do |year|
               %td= @participants[year]
             %td= @participants.values.inject(:+)
+      = high_chart("annual_dojos", @annual_dojos_chart)
 
     %h3 関連リンク
     %ul{:style => "list-style: none; margin-left: -40px;"}