Make it easier to customize allowed parameters

When customizing CONSUL, one of the most common actions is adding a new
field to a form.

This requires modifying the permitted/allowed parameters. However, in
most cases, the method returning these parameters returned an instance
of `ActionController::Parameters`, so adding more parameters to it
wasn't easy.

So customizing the code required copying the method returning those
parameters and adding the new ones. For example:

```
def something_params
  params.require(:something).permit(
    :one_consul_attribute,
    :another_consul_attribute,
    :my_custom_attribute
  )
end
```

This meant that, if the `something_params` method changed in CONSUL, the
customization of this method had to be updated as well.

So we're extracting the logic returning the parameters to a method which
returns an array. Now this code can be customized without copying the
original method:

```
alias_method :consul_allowed_params, :allowed_params

def allowed_params
  consul_allowed_params + [:my_custom_attribute]
end
```

app/controllers/admin/poll/active_polls_controller.rb

@@ -29,6 +29,10 @@ class Admin::Poll::ActivePollsController < Admin::Poll::BaseController
     end
 
     def active_poll_params
-      params.require(:active_poll).permit(translation_params(ActivePoll))
+      params.require(:active_poll).permit(allowed_params)
+    end
+
+    def allowed_params
+      [translation_params(ActivePoll)]
     end
 end

app/controllers/admin/poll/booths_controller.rb

@@ -39,6 +39,10 @@ class Admin::Poll::BoothsController < Admin::Poll::BaseController
   private
 
     def booth_params
-      params.require(:poll_booth).permit(:name, :location)
+      params.require(:poll_booth).permit(allowed_params)
+    end
+
+    def allowed_params
+      [:name, :location]
     end
 end

app/controllers/admin/poll/polls_controller.rb

@@ -76,10 +76,14 @@ class Admin::Poll::PollsController < Admin::Poll::BaseController
     end
 
     def poll_params
+      params.require(:poll).permit(allowed_params)
+    end
+
+    def allowed_params
       attributes = [:name, :starts_at, :ends_at, :geozone_restricted, :budget_id, :related_sdg_list,
                     geozone_ids: [], image_attributes: image_attributes]
 
-      params.require(:poll).permit(*attributes, *report_attributes, translation_params(Poll))
+      [*attributes, *report_attributes, translation_params(Poll)]
     end
 
     def search_params

app/controllers/admin/poll/questions/answers/images_controller.rb

@@ -32,8 +32,11 @@ class Admin::Poll::Questions::Answers::ImagesController < Admin::Poll::BaseContr
   private
 
     def images_params
-      params.require(:poll_question_answer).permit(:answer_id,
-        images_attributes: image_attributes)
+      params.require(:poll_question_answer).permit(allowed_params)
+    end
+
+    def allowed_params
+      [:answer_id, images_attributes: image_attributes]
     end
 
     def load_answer

app/controllers/admin/poll/questions/answers/videos_controller.rb

@@ -44,7 +44,11 @@ class Admin::Poll::Questions::Answers::VideosController < Admin::Poll::BaseContr
   private
 
     def video_params
-      params.require(:poll_question_answer_video).permit(:title, :url, :answer_id)
+      params.require(:poll_question_answer_video).permit(allowed_params)
+    end
+
+    def allowed_params
+      [:title, :url, :answer_id]
     end
 
     def load_answer

app/controllers/admin/poll/questions/answers_controller.rb

@@ -51,12 +51,14 @@ class Admin::Poll::Questions::AnswersController < Admin::Poll::BaseController
   private
 
     def answer_params
-      attributes = [:title, :description, :given_order, :question_id,
-        documents_attributes: document_attributes]
+      params.require(:poll_question_answer).permit(allowed_params)
+    end
 
-      params.require(:poll_question_answer).permit(
-        *attributes, translation_params(Poll::Question::Answer)
-      )
+    def allowed_params
+      attributes = [:title, :description, :given_order, :question_id,
+                    documents_attributes: document_attributes]
+
+      [*attributes, translation_params(Poll::Question::Answer)]
     end
 
     def load_answer

app/controllers/admin/poll/questions_controller.rb

@@ -54,8 +54,13 @@ class Admin::Poll::QuestionsController < Admin::Poll::BaseController
   private
 
     def question_params
+      params.require(:poll_question).permit(allowed_params)
+    end
+
+    def allowed_params
       attributes = [:poll_id, :question, :proposal_id]
-      params.require(:poll_question).permit(*attributes, translation_params(Poll::Question))
+
+      [*attributes, translation_params(Poll::Question)]
     end
 
     def search_params

app/controllers/admin/poll/shifts_controller.rb

@@ -56,9 +56,13 @@ class Admin::Poll::ShiftsController < Admin::Poll::BaseController
     end
 
     def shift_params
-      date_attributes = [:vote_collection_date, :recount_scrutiny_date]
-      attributes = [:booth_id, :officer_id, :task, date: date_attributes]
-      shift_params = params.require(:shift).permit(*attributes)
+      shift_params = params.require(:shift).permit(allowed_params)
       shift_params.merge(date: shift_params[:date]["#{shift_params[:task]}_date".to_sym])
     end
+
+    def allowed_params
+      date_attributes = [:vote_collection_date, :recount_scrutiny_date]
+
+      [:booth_id, :officer_id, :task, date: date_attributes]
+    end
 end