Generate QR codes when not present and asked for

app/controllers/contestants_controller.rb

@@ -123,6 +123,12 @@ class ContestantsController < ApplicationController
   def generate_qrcodes
     authorize @contest
 
+    @contest.contestants.each do |contestant|
+      if !contestant.qrcode.present?
+        contestant.public_generate_qrcode
+        contestant.save
+      end
+    end
     @contestants = @contest.contestants.sort_by { |contestant| contestant.name }
   end