Add Settings and respect them

app/controllers/dashboard_controller.rb

       .where(attending: nil)
       .paginate(page: params[:nrpage], per_page: 5)
   end
+
+  def settings
+    @person = current_person
+    @send_attendance_reminder = @person.send_attendance_reminder
+  end
+
+  def update_email_settings
+    p = current_person
+    p.send_attendance_reminder = params[:send_attendance_reminder]
+    p.save
+
+    flash_message(:success, t('settings.saved'))
+    redirect_to root_path
+  end
 end

app/models/participant.rb

     self.notes = notes
     self.save
 
+    return unless self.person.send_attendance_reminder
     ParticipantMailer.attendance_reminder(self.person, self.activity).deliver_later
   end
 

app/views/dashboard/settings.html.haml

+%h1
+  = t 'settings.settings'
+
+%h2
+  = t 'settings.email_settings'
+
+= form_tag(update_email_settings_path, method: "post", class: "form") do
+  .row
+    .col-md-4
+      -#= hidden_field_tag(:send_attendance_reminder, "off")
+      %label
+        = check_box_tag(:send_attendance_reminder, 'send_attendance_reminder', @send_attendance_reminder)
+        = t('settings.names.send_attendance_reminder')
+    .col-md-6
+      %p
+        %em= t 'settings.descriptions.send_attendance_reminder'
+
+  = submit_tag t('helpers.submit.submit', model: t('settings.settings'))

app/views/people/show.html.erb

 <ul>
   <li><%= @person.birth_date %></li>
   <li><%= @person.email %></li>
+  <li>AttendanceReminder: <%= @person.send_attendance_reminder.to_i %></li>
 </ul>
 <%= link_to t(:edit), edit_person_path(@person) %> |
 <%= link_to t(:back), people_path %>

app/views/shared/_menu.html.haml

 
       %ul.nav.navbar-nav.navbar-right
         %li
-          = link_to current_person do
-            = current_person.full_name
+          = link_to settings_path do
+            %i.fa.fa-cogs{'aria-hidden': true}
+            = t 'settings.settings'
         %li
           = link_to logout_path, confirm: "Really log out?", method: :delete do
             %i.fa.fa-sign-out{'aria-hidden': true}

config/locales/settings_en.yml

+en:
+  settings:
+    settings: "Preferences"
+    saved: "Preferences saved!"
+    email_settings: "Email notifications"
+
+    names:
+      send_attendance_reminder: "Send notification on auto-respond"
+
+    descriptions:
+      send_attendance_reminder: "Receive an email if you haven't responded to an activity and your response is automatically set to 'attending'. When youreceive this reminder, you still have the possibility to change your response."

config/locales/settings_nl.yml

+nl:
+  settings:
+    settings: "Instellingen"
+    saved: "Instellingen opgeslagen!"
+    email_settings: "Emailnotificaties"
+
+    names:
+      send_attendance_reminder: "Stuur een herinnering bij niet gereageerd"
+
+    descriptions:
+      send_attendance_reminder: "Ontvang een email als je niet hebt gereageerd op een activiteit en je reactie automatisch op 'aanwezig' wordt gezet. Wanneer je deze herinnering ontvangt is het nog mogelijk om je reactie aan te passen."

config/routes.rb

   get 'dashboard/home'
 
   root to: 'dashboard#home'
+  get 'settings', to: 'dashboard#settings', as: :settings
+  post 'settings', to: 'dashboard#update_email_settings', as: :update_email_settings
 
   get  'login', to: 'authentication#login_form', as: :login
   post 'login', to: 'authentication#login'

db/migrate/20170917140643_add_send_attendance_reminder_to_person.rb

+class AddSendAttendanceReminderToPerson < ActiveRecord::Migration[5.0]
+  def change
+    add_column :people, :send_attendance_reminder, :boolean, default: true
+  end
+end

db/schema.rb

 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170917093221) do
+ActiveRecord::Schema.define(version: 20170917140643) do
 
   create_table "activities", force: :cascade do |t|
     t.string   "name"
     t.date     "birth_date"
     t.string   "email"
     t.boolean  "is_admin"
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
+    t.datetime "created_at",                              null: false
+    t.datetime "updated_at",                              null: false
+    t.boolean  "send_attendance_reminder", default: true
     t.index ["email"], name: "index_people_on_email", unique: true
   end