lib/rails_admin/config/action/edit.rb

edit.rb

# ほぼオリジナルのパクリ（https://github.com/sferik/rails_admin/blob/master/lib/rails_admin/config/actions/edit.rb）
# 今回必要になる部分を追記する
 
module RailsAdmin
  module Config
    module Actions
      class Edit < RailsAdmin::Config::Actions::Base
        RailsAdmin::Config::Actions.register(self)
 
        register_instance_option :member do
          true
        end
 
        register_instance_option :http_methods do
          [:get, :put]
        end
 
        register_instance_option :controller do
          proc do
            if request.get? # EDIT
　　
            # ↓ 挿入部分 ↓
            if @model_name == "Product"
              @order_objects = Product.joins(:images).includes(:images).find(@object.id).images
            end
            # ↑ 挿入部分 ↑
　　
              respond_to do |format|
                format.html { render @action.template_name }
                format.js   { render @action.template_name, layout: false }
              end
 
            elsif request.put? # UPDATE
              sanitize_params_for!(request.xhr? ? :modal : :update)
 
              @object.set_attributes(params[@abstract_model.param_key])
              @authorization_adapter && @authorization_adapter.attributes_for(:update, @abstract_model).each do |name, value|
                @object.send("#{name}=", value)
              end
              changes = @object.changes
 
              # ↓ 挿入部分 ↓ 
              if @model_name == "Product"
                params[:products].each do |params_product|
                  Item.find(params_product[:id]).update_attributes(order: params_product[:order])
                end
              end
　　　　　　　# ↑ 挿入部分 ↑
　　
              if @object.save
                @auditing_adapter && @auditing_adapter.update_object(@object, @abstract_model, _current_user, changes)
                respond_to do |format|
                  format.html { redirect_to_on_success }
                  format.js { render json: {id: @object.id.to_s, label: @model_config.with(object: @object).object_label} }
                end
              else
                handle_save_error :edit
              end
 
            end
          end
        end
 
        register_instance_option :link_icon do
          'icon-pencil'
        end
      end
    end
  end
end