Questions: fixes, redesign form, fix edit error

app/models/ability.rb

@@ -173,6 +173,7 @@ class Ability
     can :manage, Question do |question|
       !(question.conferences.pluck(:id) & conf_ids_for_info_desk).empty?
     end
+    can [ :show, :toggle_question ], Question, global: true
   end
 
   def signed_in_with_volunteers_coordinator_role(user)

app/models/answer.rb

@@ -1,8 +1,21 @@
 class Answer < ActiveRecord::Base
   attr_accessible :title
 
-  has_many :qanswers
+  has_many :qanswers, dependent: :destroy
   has_many :questions, through: :qanswers
 
   validates :title, presence: true
+  validate :no_modification_if_used
+
+  def no_modification_if_used
+    errors.add('', 'cannot be altered or deleted, if they are being used.') if self.title_changed? && self.questions.any?
+  end
+
+  # Gets answer, question, conference
+  ## Returns
+  # the amount of replies for a given answer
+  # + integer +
+  def sum_replies question, conference
+    self.qanswers.find_by(question: question).registrations.where(conference: conference).count
+  end
 end

app/models/qanswer.rb

@@ -2,7 +2,7 @@ class Qanswer < ActiveRecord::Base
   attr_accessible :question_id, :answer_id
 
   belongs_to :question
-  belongs_to :answer, dependent: :delete
+  belongs_to :answer
 
   has_and_belongs_to_many :registrations
 

app/models/question.rb

@@ -8,12 +8,5 @@ class Question < ActiveRecord::Base
   has_many :answers, through: :qanswers, dependent: :delete_all
 
   validates :title, :question_type_id, presence: true
-  validate :existing_answers
   accepts_nested_attributes_for :answers, allow_destroy: true
-
-  private
-
-  def existing_answers
-    errors.add(:base, 'Must have answers') if self.answers.blank?
-  end
 end