Add admin action to regenerate QR codes

app/controllers/users_controller.rb

@@ -73,6 +73,15 @@ class UsersController < ApplicationController
     redirect_to users_path, notice: "Updated contestants: #{updated}/#{total}"
   end
 
+  def regenerate_qrcodes
+    authorize :user
+
+    Contestant.all.each do |contestant|
+      contestant.regenerate_qrcode
+      contestant.save
+    end
+  end
+
   private
 
   def set_user

app/models/contestant.rb

@@ -43,6 +43,10 @@ class Contestant < ApplicationRecord
     end
   end
 
+  def regenerate_qrcode
+    generate_qrcode
+  end
+
   private
 
   def initialize_time_seconds_if_empty

app/policies/user_policy.rb

@@ -30,4 +30,8 @@ class UserPolicy < ApplicationPolicy
   def update_contestants?
     user.admin?
   end
+
+  def regenerate_qrcodes?
+    user.admin?
+  end
 end

app/views/users/index.html.slim

@@ -25,4 +25,5 @@ table.table.table-striped.table-hover
   .col
     a.btn.btn-primary href=new_user_path
       | New user
-    = button_to "Update contestants", "/update_contestants", method: :post, class: "mt-3 btn btn-success"
+    = button_to "Update contestants", "/update_contestants", method: :post, class: "mt-3 btn btn-success"
+    = button_to "Regenerate QR codes", "/regenerate_qrcodes", method: :post, class: "mt-3 btn btn-success"