Async and spinner helper in action

importing.rb

      @hud = spinner_on labelText: "Importing..."

      Friend.eq(user: User.current_user).order(name: :asc).fetchAll do |friends|
        import_queue = Dispatch::Queue.new("com.clearsightstudio.bigday.import_address_book_contacts")
        friend_lookup = []
        if friends
          friends.each do |f|
            friend_lookup << f.name
          end
        end
        num = 0
        self.imported_people.each do |person|
          if person.first_name && person.first_name.length > 0
            num += 1
            import_queue.async do
              # TODO: Add more sophisticated deduplication code.
              # Right now, I'm only checking first/last names to prevent duplicates.
              # Obviously this will be inadequate in the future.
              full_name = "#{person.first_name} #{person.last_name}"
              unless friend_lookup.include? full_name
                Dispatch::Queue.main.async do
                  update_hud(full_name)
                end
                p = Friend.new
                p.name = full_name
                p.user = User.current_user
                p.save
              end
            end
          end
        end
        import_queue.async do
          Dispatch::Queue.main.async do 
            done_importing_friends
          end
        end
      end