rails 4: AbstractController::DoubleRenderError 格式

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，因为重定向和呈现不在同一个块中...

这是我的控制器

class GroupsController < ApplicationController respond_to: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
...

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)

这是一个相当标准的 .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 %>

这是怎么回事？为什么？感谢反馈

更新 1 =======

根据 Pavan 的评论，我更新了创建代码，并且还添加了响应程序 gem（rails 版本 4.2.4：不兼容版本说明 - 3.2 respond_with / Class-等级respond_to)

respond_with and the corresponding class-level respond_to have been moved to the responders gem. Add gem 'responders', '~> 2.0' to your Gemfile to use it:

我的 :new 和 :create 代码现在

    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 仍然引发同样的错误

 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

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

您应该将 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

此外，由于您正在使用 Rails 4，因此您应该使用 强参数.

private

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

并改变

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

到

@group = Group.new(group_params)

Answer 2

如问题评论中所述，action的代码没有问题

但是，after_filter 之一正在调用 render/redirect_to，这会导致 AbstractController::DoubleRenderError 错误。

对于作者的问题，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，并且不可能得到 AbstractController::DoubleRenderError 错误。

rails 4: AbstractController::DoubleRenderError 格式

rails 4: AbstractController::DoubleRenderError with format

rendering

ruby-on-rails-4