div#tracks = form.simple_fields_for :tracks do |ff| .col-lg-6 .panel.panel-default .panel-body = ff.input :name = ff.input :color, as: :color = ff.input :description .panel-footer.text-right = ff.link_to_remove t('actions.destroy.button', model: Track.model_name.human), class: ['btn', 'btn-danger', ff.object.events.any? ? 'disabled' : nil] .col-lg-6 .panel.panel-default .panel-body.text-right = form.link_to_add t('actions.create.button', model: Track.model_name.human), :tracks, data: {target: '#tracks'}, class: 'btn btn-success'