Ruby on rails 用于nil:NilClass的Rails未定义方法*

我有一个问题，我做了一些研究，从我的研究中，我发现正在使用的变量是空的，但是我不确定为什么它是空的，也许这对其他人来说是显而易见的

我试图在另一个控制器的页面上显示嵌套表单，我使用了嵌套资源，我认为这可能是我的问题，但不确定如何解决它

获取以下错误：

undefined method `submission' for nil:NilClass

class Submission < ActiveRecord::Base
    belongs_to :question
    belongs_to :member
end

class Members::Question < ActiveRecord::Base
  has_many :submissions
end

def create

        @question =  Members::Question.find(params[:question_id])
        @submission.member_id =  current_member.id
        @submission = @question.submissions.create(params[:submission].permit(:content, :question_id))

*Redirect Method Here * 

end

  namespace :members do
    resources :questions,  only: [:index,:show] do
      resources :submissions 
    end
  end

项目结构 主文件夹 -成员 --问题 --意见书

概念：

undefined method `submission' for nil:NilClass

class Submission < ActiveRecord::Base
    belongs_to :question
    belongs_to :member
end

class Members::Question < ActiveRecord::Base
  has_many :submissions
end

def create

        @question =  Members::Question.find(params[:question_id])
        @submission.member_id =  current_member.id
        @submission = @question.submissions.create(params[:submission].permit(:content, :question_id))

*Redirect Method Here * 

end

  namespace :members do
    resources :questions,  only: [:index,:show] do
      resources :submissions 
    end
  end

问题-你有很多意见书吗 提交-属于-问题

提交模式：

undefined method `submission' for nil:NilClass

class Submission < ActiveRecord::Base
    belongs_to :question
    belongs_to :member
end

class Members::Question < ActiveRecord::Base
  has_many :submissions
end

def create

        @question =  Members::Question.find(params[:question_id])
        @submission.member_id =  current_member.id
        @submission = @question.submissions.create(params[:submission].permit(:content, :question_id))

*Redirect Method Here * 

end

  namespace :members do
    resources :questions,  only: [:index,:show] do
      resources :submissions 
    end
  end

在表格中，我使用以下方法：

<%= form_for([@question, @question.submission.build]) do |f| %>
  <% if @submission.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@submission.errors.count, "error") %> prohibited this submission from being saved:</h2>

      <ul>
      <% @submission.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :content %><br>
    <%= f.text_area :content %>
  </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

有人知道我哪里出错了吗

---

非常感谢您的帮助。

我已经解决了这个问题，谢谢您的建议，我使用了错误的变量，我使用了@question，因为它是嵌套的，正确的变量是@members\u question

提交控制器

def create

        @members_question =  Members::Question.find(params[:question_id])
        @submission = @members_question.submissions.create(params[:submission].permit(:content, :question_id))
    @submission.member_id =  current_member.id

end

\u form.html.erb

<%= form_for([@members_question, @members_question.submissions.build]) do |f| %>

  <div class="field">
    <%= f.label :content %><br>
    <%= f.text_area :content %>
  </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

您的控制器是否在此处返回对象

@question=Members:：question.find（参数[：question\u id]）

。。做一个

@questions。在那一行之后检查
，发现视图中有打字错误
@question.submission.build
应该是
@questions.submissions.build
@MikDiet我两个都试过了，都不起作用。@sa77我试过，但在网站或终端上看不到任何输出，我希望在哪里看到输出？@user7391609在哪一行抛出错误？变量的名称完全不相关，它只需在控制器和表单中匹配即可。