rails 4: AbstractController::DoubleRenderError with format

Question

我正在通过 Ajax 请求创建组记录，并收到此错误（在这两种情况下，@group 有效或无效）

Started POST "/groups" for ::1 at 2015-10-28 17:47:08 +0100
Processing by GroupsController#create as JS

AbstractController::DoubleRenderError - Render and/or redirect were called multiple times in this action. Please.....

我不明白为什么，因为重定向和渲染不在同一个块中......

这是我的控制器

类 GroupsController

def create
    @group = Group.new(company_id: current_user.company_id, name: params[:name] )
    if @group.save?
      respond_to do |format|
        format.html { redirect_to groups_path, notice: 'Group was successfully created.'}
        format.js
      end
    else 
      respond_to  do |format|
        format.html { redirect_to new_group_path }
        format.js
      end
    end
end
...

在尝试渲染 create.js 时似乎发生了错误

 Rendered groups/create.js.erb (6.5ms)
 Completed 500 Internal Server Error in 48784ms (Views: 46.2ms |    ActiveRecord: 4.7ms)

这是一个非常标准的 .js.erb 文件

    <% if  @group.errors.blank? -%> 
      $('#groupModal').modal('hide');
    <% else %>
      $( "#modalGroupAlert" ).removeClass('alert-info');
      $( "#modalGroupAlert" ).addClass('alert-danger');
      $( "#modalGroupAlert span" ).replaceWith( "<span><%= nicer_display_errors(@group.errors) %></span>" );
      $( "#modalGroupAlert" ).show();
    <% end %>

发生了什么事？为什么？感谢反馈

更新 1 =======

根据 Pavan cmets，我更新了我的创建代码，还添加了响应程序 gem（rails 版本 4.2.4：不兼容性发布说明 - 3.2 respond_with / Class-Level respond_to）

respond_with 和相应的类级 respond_to 已移至响应者 gem。将 gem 'responders', '~> 2.0' 添加到您的 Gemfile 以使用它：

我的 :new 和 :create 代码现在是

    def new
      @group = Group.new()
      authorize @group
      respond_with @group
    end

    def create
      @group =  Group.new(group_params)
      respond_to do |format|
        if @group.save #remove ? here
          format.html { redirect_to groups_path }
          format.js
        else 
          format.html { redirect_to new_group_path }
          format.js
        end
      end
    end

:new.js 被正确处理

 Started GET "/groups/new.js?_=1446101853822" for ::1 at 2015-10-29 07:57:40 +0100
 Processing by GroupsController#new as JS
 ...
 Rendered groups/_new_modal_content.html.erb (15.8ms)
 Rendered groups/new.js.erb (23.6ms)
 Completed 200 OK in 84ms (Views: 65.7ms | ActiveRecord: 3.7ms)

但是 :create 仍然出现同样的错误

 Started POST "/groups" for ::1 at 2015-10-29 07:57:48 +0100
 Processing by GroupsController#create as JS
 ...
 Rendered groups/create.js.erb (0.4ms)

 Completed 500 Internal Server Error in 71ms (Views: 31.6ms | ActiveRecord: 21.2ms)
 AbstractController::DoubleRenderError - Render and/or redirect were called multiple times in this action. Please...

Answer 1

正如问题的cmets中解释的那样，动作的代码没有问题。

但是，其中一个 after_filter 正在调用 render/redirect_to，这会导致 AbstractController::DoubleRenderError 错误。

就作者的问题而言，它似乎来自 Pundit after_filters。

一种可能的解决方案是将这些过滤器用作 before_filters 而不是 after_filters。事实上，当 before_filter 调用 render 或 redirect_to 时，动作代码并没有被执行，不可能得到AbstractController::DoubleRenderError 错误。

Answer 2

AbstractController::DoubleRenderError - 渲染和/或重定向是 在此操作中多次调用

您应该将您的 create 操作更改为以下

def create
  @group = Group.new(company_id: current_user.company_id, name: params[:name] )

  respond_to do |format|
    if @group.save #remove ? here
      format.html { redirect_to groups_path, notice: 'Group was successfully created.'}
      format.js
    else 
      format.html { redirect_to new_group_path }
      format.js
    end
  end
end

在您使用 Rails 4 时，您应该使用 strong 参数。

private

def group_params
  params.require(:group).permit(:name).merge(company_id: current_user.comapany_id)
end

然后改变

@group = Group.new(company_id: current_user.company_id, name: params[:name] )

到

@group = Group.new(group_params)