Add a csv download button to Rails view

collection_objects.html.erb

<p>Generate Outstanding Migration CSV Report: <%= link_to("CSV Report", admin_dashboard_collection_objects_path(format: :csv), class: "btn btn-success",) %></p>

dashboard_controller.rb

def collection_objects
  @museum_collections = museum_collections
  respond_to do |format|
    format.html
    format.csv do
      send_data @museum_collections.to_csv('outstanding'),
                filename: "outstanding-#{Time.zone.today}.csv"
    end
  end
end

museum_collection.rb

def self.to_csv(scope = 'outstanding')
  CSV.generate do |csv|
    csv << %w[museum_collection_id museum_collection_slug museum_collection_status
              enhanced_object_id enhanced?]
    all.find_each do |mc|
      mc.enhanced_objects.each do |eo|
        if scope == 'outstanding'
          unless eo.accessioned
            csv << [mc.id, mc.name, mc.state, eo.id, eo.accessioned]
          end
        else
          csv << [mc.id, mc.name, mc.state, eo.id, eo.accessioned]
        end
      end
    end
  end
end