Subgroup division plumbing

app/models/activity.rb

   # @!attribute reminder_done
   #   @return [Boolean]
   #     whether or not sending the reminder has finished.
+  #
+  # @!attribute subgroup_division_enabled
+  #   @return [Boolean]
+  #     whether automatic subgroup division on the deadline is enabled.
+  #
+  # @!attribute subgroup_division_done
+  #   @return [Boolean]
+  #     whether subgroup division has been performed.
 
   belongs_to :group
 
   validate  :deadline_before_start, unless: "self.deadline.blank?"
   validate  :end_after_start,       unless: "self.end.blank?"
   validate  :reminder_before_deadline, unless: "self.reminder_at.blank?"
+  validate  :subgroups_for_division_present, on: :update
 
   after_create :create_missing_participants!
   after_create :copy_default_subgroups!
-  after_commit :schedule_reminder, if: Proc.new {|a| a.previous_changes["reminder_at"] }
+  after_commit :schedule_reminder,
+               if: Proc.new { |a| a.previous_changes["reminder_at"] }
+  after_commit :schedule_subgroup_division,
+               if: Proc.new { |a| (a.previous_changes['deadline'] ||
+                                   a.previous_changes['subgroup_division_enabled']) &&
+                                  !a.subgroup_division_done &&
+                                  a.subgroup_division_enabled }
 
   # Get all people (not participants) that are organizers. Does not include
   # group leaders, although they may modify the activity as well.
   def copy_default_subgroups!
     defaults = self.group.default_subgroups
 
+    # If there are no subgroups, there cannot be subgroup division.
+    self.update_attribute(:subgroup_division_enabled, false) if defaults.none?
+
     defaults.each do |dsg|
       sg = Subgroup.new(activity: self)
       sg.name = dsg.name
       sg.is_assignable = dsg.is_assignable
       sg.save! # Should never fail, as DSG and SG have identical validation, and names cannot clash.
     end
+
   end
 
   # Create multiple Activities from data in a CSV file, assign to a group, return.
     self.delay(run_at: self.reminder_at).send_reminder
   end
 
+  def schedule_subgroup_division
+    return if self.deadline.nil? || self.subgroup_division_done
+
+    self.delay(run_at: self.deadline).assign_subgroups!
+  end
+
   # Assign a subgroup to all attending participants without one.
   def assign_subgroups!
     # Sanity check: we need subgroups to divide into.

app/views/activities/_form.html.erb

       <%= f.label :reminder_at %>
       <%= f.datetime_field :reminder_at, class: 'form-control' %>
     </div>
+    <div class="form-group">
+      <div class="check-box">
+        <%= f.check_box(:subgroup_division_enabled) %>
+        <%= t 'activerecord.attributes.activity.subgroup_division_enabled' %>
+      </div>
     <%= f.submit class: 'btn btn-primary' %>
   </div>
 <% end %>

app/views/activities/index.html.haml

   %thead
     %tr
       %th
-        = t 'activerecord.attributes.activities.name'
+        = t 'activerecord.attributes.activity.name'
 
       %th
-        = t 'activerecord.attributes.activities.start'
+        = t 'activerecord.attributes.activity.start'
 
       %th
         P/A/?

config/locales/activities/en.yml

     errors:
       must_be_before_start: "must be before start"
       must_be_after_start: "must be after start"
+      must_be_before_deadline: "must be before deadline"
       already_in: "person already participates in activity"
+      cannot_divide_without_subgroups: "a divisible subgroup must exist"
 
     participant:
       singular: "participant"

config/locales/activities/nl.yml

       must_be_after_start: "moet na start zijn"
       must_be_before_deadline: "moet voor deadline zijn"
       already_in: "persoon doet al mee aan activiteit"
+      cannot_divide_without_subgroups: "moet indeelbare subgroep hebben"
 
     participant:
       singular: "deelnemer"

config/locales/translation_nl.yml

         reminder_at: Herinnering om
         reminder_done: Herinnering verstuurd
         subgroups: :activerecord.models.subgroup.other
+        subgroup_division_enabled: Subgroepen indelen
+        subgroup_division_done: Subgroepen ingedeeld
 
       group:
         activities: Activiteiten  #g