ActiveAdmin で、belongs_to, accepts_nested_attributes_for を設定したmodelも同時に表示・編集する
ActiveAdmin.register UserLogin do # ... form do |f| f.inputs nil, for: [:user, f.object.user || User.new] do |fc| fc.input :icon fc.input :full_name fc.input :is_deleted end f.inputs nil do f.input :email f.input :password f.input :password_confirmation f.input :is_deleted end f.actions end show do |f| panel I18n.t("active_admin.details", model: User.model_name.human) do attributes_table_for f.user do row :icon row :full_name row :is_deleted row :created_at row :updated_at end end attributes_table do row :id row :email row :is_deleted row :created_at row :updated_at end active_admin_comments if active_admin_config.comments? end