Rails: 如何呈现嵌套的部分

Question

我正在尝试使用 Rails 4 和 Simple Form 制作一个应用程序。

我有一个项目模型、一个 project_questions 模型和一个项目答案模型。

协会是：

Project.rb:

   has_many :project_questions, dependent: :destroy#, through: :projects
  accepts_nested_attributes_for :project_questions

Project_question.rb:

belongs_to :project#, counter_cache: true
  has_one :project_answer, dependent: :destroy
  belongs_to :user
  accepts_nested_attributes_for :project_answer

项目answer.rb：

  belongs_to :project_questions#, counter_cache: true
  belongs_to :user

我的路线是嵌套的：

  resources :projects do
    resources :project_questions do
      resources :project_answers
    end
  end

我的项目展示，包括部分展示关于项目的问题。

  <%= render 'project_questions/pqps' %>

在该项目问题部分 (pqps) 中，我试图呈现部分项目答案，以便答案位于问题下方。

  <% @project.project_questions.each do |singleQuestion| %>

      <div class="categorytitle">
        <%= singleQuestion.title %>

      </div>
      <div class="generaltext">
        <%= singleQuestion.try(:content) %>
      </div>
      <span class="editproject">
        <% if current_user.id == @project.creator_id %>

            <%= link_to 'Answer this question', new_project_project_question_project_answer_path(:project_id => @project.id, :project_question_id => singleQuestion.id) %>
<% else %>
            <%= render 'project_answers/answers' %>

<% end %>

我很挣扎，因为我在 project_answer 部分视图中的代码是：

        <%= @project.project_questions.project_answers.answer %>

当我尝试这个时，我得到这个错误：

undefined method `project_answers' for #`<ActiveRecord::Associations::CollectionProxy::ActiveRecord_Associations_CollectionProxy_ProjectQuestion:0x000001039ebcc8>`

我已经尝试了该项目答案代码行的所有形式和复数化不同位的组合，但没有任何效果。

当我尝试这样回答时： <%= @project.project_questions.project_answer.answer %>

undefined method `project_answer' for #<ActiveRecord::Associations::CollectionProxy::ActiveRecord_Associations_CollectionProxy_ProjectQuestion:0x00000102b59318>

我不明白这是为什么。

在我的项目答案控制器中，我有：

class ProjectAnswersController < ApplicationController
  before_action :set_project
  before_action :set_project_question
  before_action :set_project_answer, only: [:show, :edit, :update, :destroy]


  # GET /project_answers
  # GET /project_answers.json
  def index
    @project_answers = ProjectAnswer.all
  end

  # GET /project_answers/1
  # GET /project_answers/1.json
  def show
  end

  # GET /project_answers/new


  def new
    @project_answer = @project_question.build_project_answer
  end

  # GET /project_answers/1/edit
  def edit
  end

  # POST /project_answers
  # POST /project_answers.json
  def create
    @project_answer = @project_question.build_project_answer(project_answer_params)


    respond_to do |format|
      if @project_answer.save
        format.html { redirect_to @project, notice: 'Project answer was successfully created.' }
        format.json { render action: 'show', status: :created, location: @project_answer }
      else
        format.html { render action: 'new' }
        format.json { render json: @project_answer.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /project_answers/1
  # PATCH/PUT /project_answers/1.json
  def update
    respond_to do |format|
      if @project_answer.update(project_answer_params)
        format.html { redirect_to @project_answer, notice: 'Project answer was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @project_answer.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /project_answers/1
  # DELETE /project_answers/1.json
  def destroy
    @project_answer.destroy
    respond_to do |format|
      format.html { redirect_to project_answers_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.

    def set_project
      @project = Project.find(params[:project_id])
    end

    def set_project_question
      @project_question = @project.project_questions.find(params[:project_question_id])
    end


  def set_project_answer
      @project_answer = ProjectAnswer.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def project_answer_params
      params[:project_answer].permit(:answer, :project_question_id, :id)
    end
end

我原以为应该让我只使用@project.answer.answer，但我也试过了，但它也不起作用。

任何人都可以看到我需要做什么来呈现问题的答案吗？

Answer 1

如果你正确阅读了你的错误

undefined method project_answers' for
#<ActiveRecord::Associations::CollectionProxy::ActiveRecord_Associations_CollectionProxy_ProjectQuestion:0x000001039ebcc8>

它清楚地指出 您正在调用 project_answers 集合而不是单个记录。此外，您在 ProjectQuestion 和 ProjectAnswer 模型上有 1-1 关联，因此它应该是 project_answer 而不是 project_answers

修复：

根据您的局部中的 HTML，您可以使用其中的任何一个：

<%= render partial: 'project_answers/answers', locals: {some_local_variable_used_in_partial: singleQuestion.project_answer}  %>

有关详细信息，请查看 using partials

编辑：

您仍在调用 project_answer 集合。您需要遍历 project_questions 然后为其呈现答案。在您的部分内容中，您需要：

<% @project.project_questions.each do |question| %>
  <%= question.project_answer.answer %>
<% end %>

Rails: 如何呈现嵌套的部分

Rails: How to render a nested partial

ruby-on-rails

path