rails 4: AbstractController::DoubleRenderError with format

Question

我正在通过Ajax请求创建一个组记录，并得到这个错误（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块。。。

这是我的控制器

class GroupsController<应用程序控制器响应：html，：js

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
...

该错误似乎是在尝试渲染create.js 时发生的

 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？感谢的反馈

更新1======

根据Pavan的评论，我更新了我的创建代码，还添加了responsers gem（rails版本4.2.4：不兼容发布说明-3.2 responsd_with/Class Level responsd_to）

responsd_with和相应的类级别responsd_to已被移动到responsersgem。将gem"responsivers"，"~>2.0"添加到您的Gemfile以使用它：

my: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仍然会引发相同的错误

 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

正如问题注释中所解释的，操作代码没有问题。

但是，其中一个after_filter正在调用render/redirect_to，这导致了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_filter。事实上，当before_filter调用render或redirect_to时，不会执行操作代码，也不可能得到AbstractController::DoubleRenderError错误。

Answer 2

AbstractController:：DoubleRenderError-渲染和/或重定向在该操作中多次调用

您应该将create操作更改为低于

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

此外，当您使用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

并更改

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

至

@group = Group.new(group_params)