Shifts are destroyed when a booths is unassigned. An alert appears if there are shifts, but it doesn't if there aren't.

app/models/poll.rb

@@ -90,8 +90,4 @@ class Poll < ActiveRecord::Base
     end
   end
 
-  def shifts_in_booth(booth_id)
-    officer_assignments.where(booth_assignment_id: booth_assignments.where(booth_id: booth_id).pluck(:id)).pluck(:officer_id).uniq
-  end
-
 end

app/models/poll/booth_assignment.rb

@@ -3,23 +3,26 @@ class Poll
     belongs_to :booth
     belongs_to :poll
 
+    before_destroy :destroy_poll_shifts, only: :destroy
+
     has_many :officer_assignments, class_name: "Poll::OfficerAssignment", dependent: :destroy
     has_many :officers, through: :officer_assignments
     has_many :voters
     has_many :partial_results
     has_many :recounts
 
-    before_destroy :destroy_poll_shifts
-    
-    def has_shifts?
-      
+    def shifts?
+      shifts.empty? ? false : true
     end
 
     private
 
+      def shifts
+        Poll::Shift.where(booth_id: booth_id, officer_id: officer_assignments.pluck(:officer_id), date: officer_assignments.pluck(:date))
+      end
+
       def destroy_poll_shifts
-#        officers = poll.officers_in_booth(booth.id)
-#        Poll::Shift.where(officer_id: officers, booth_id: booth.id)
+        shifts.destroy_all
       end
   end
 end

app/views/admin/poll/booth_assignments/_booth_assignment.html.erb

@@ -15,7 +15,7 @@
                 remote: true,
                 title: t("admin.booth_assignments.manage.actions.unassign"),
                 class: "button hollow alert #{@poll.expired? ? 'disabled' : ''}",
-                data: (booth_assignment.has_shifts? ? {confirm: "Are you sure?"} : nil) %>
+                data: (booth_assignment.shifts? ? {confirm: "#{t("admin.poll_booth_assignments.alert.shifts")}"} : nil) %>
   </td>
 <% else %>
   <td>

config/locales/en/admin.yml

@@ -544,6 +544,8 @@ en:
           assign: Assign booth
           unassign: Unassign booth
     poll_booth_assignments:
+      alert:
+        shifts: "There are shifts associated to this booth. If you remove the booth assignment, the shifts will be also deleted. Continue?"
       flash:
         destroy: "Booth not assigned anymore"
         create: "Booth assigned"

config/locales/es/admin.yml

@@ -544,6 +544,8 @@ es:
           assign: Assign booth
           unassign: Unassign booth
     poll_booth_assignments:
+      alert:
+        shifts: "Hay turnos asignados para esta urna. Si la desasignas, esos turnos se eliminarán. ¿Deseas continuar?"
       flash:
         destroy: "Urna desasignada"
         create: "Urna asignada"