attendee_names_controller.rb

require "csv"

class Events::AttendeeNamesController < ApplicationController
  before_action :authenticate_user!
  before_action :find_event

  def index
    authorize @event, :edit?

    rsvps = @event.rsvps.where(role_id: Role.attendee_role_ids_with_organizers)

    respond_to do |format|
      format.csv do
        send_data(attendee_csv_data(rsvps), type: :csv)
      end
    end
  end

  private

  def find_event
    @event = Event.find_by(id: params[:event_id])
  end

  def attendee_csv_data(rsvps)
    CSV.generate do |csv|
      csv << ['Last Name', 'First Name']

      rsvps.includes(:user).joins(:bridgetroll_user).order('users.last_name ASC, users.first_name ASC').each do |rsvp|
        csv << [rsvp.user.last_name, rsvp.user.first_name]
      end
    end
  end
end