在铁轨中使用内部资源7

Question

我是铁路的新手。我知道，将路线放置得比两个层次更深是不好的做法。但是，如果我将它们降低到两个级别，我会遇到其他错误。因此，现在我不知道如何保存深层路线。

doutes.rb文件：

resources :posts do
 resources :post_users
 resources :comments
 resources :tasks

 resources :discussions do 
  resources :answers
 end
end

answers_controller.rb file：

class AnswersController < ApplicationController
 before_action :authenticate_user!
 before_action :set_answer, only: %i[ show edit update destroy ]

 # GET /answers or /answers.json
 def index
  @answers = Answer.all
 end

 # GET /answers/1 or /answers/1.json
 def show
 end

 # GET /answers/new
 def new
  @answer = Answer.new
 end

 # GET /answers/1/edit
 def edit
 end

 # POST /answers or /answers.json
 def create
  @post = Post.find(params[:post_id])
  @discussion = @post.discussions.find(params[:discussion_id])
  @answer = @discussion.answers.create(answer_params)
  @answer.user = current_user

 if @answer.save
  flash[:notice] = "Answer has been created"
  redirect_to post_path(@post)
 else
  flash[:alert] = "Answer has not been created"
  redirect_to post_path(@post)
 end
end

# PATCH/PUT /answers/1 or /answers/1.json
def update
 @post = Post.find(params[:post_id])
 @discussion = @post.discussions.find(params[:discussion_id])
 @answer = @discussion.answers.find(params[:id])

 respond_to do |format|
  if @answer.update(answer_params)
    format.html { redirect_to post_url(@post), notice: 'Answer was successfully updated.' }
   else
     format.html { redirect_to post_url(@post), alert: 'Answer was not updated.' }
   end
  end
end

# DELETE /answers/1 or /answers/1.json
def destroy
 @answer = @discussion.answers.find(params[:id])
 @answer.destroy

 redirect_to post_path(@post)

 # respond_to do |format|
 #   format.html { redirect_to answers_url, notice: "Answer was successfully destroyed." }
 #   format.json { head :no_content }
 # end
 end

 private
  # Use callbacks to share common setup or constraints between actions.
  def set_answer
   @answer = Answer.find(params[:id])
  end

  # Only allow a list of trusted parameters through.
  def answer_params
   params.require(:answer).permit(:body)
  end
 end

descorgions_controller.rb file：

class DiscussionsController < ApplicationController
 before_action :authenticate_user!
 before_action :set_discussion, only: %i[ show edit update destroy ]


 # GET /discussions or /discussions.json
 def index
  @discussions = Discussion.all
 end

 # GET /discussions/1 or /discussions/1.json
 def show
  @answers = @discussion.answers.order(created_at: :desc)
 end

 # GET /discussions/new      
 def new
  @discussion = Discussion.new
 end

 # GET /discussions/1/edit
 def edit
 end

 # POST /discussions or /discussions.json
 def create
   @discussion = @post.discussions.create(discussion_params)
   @discussion.user = current_user

   if @discussion.save
    flash[:notice] = "Discussion has been created"
    redirect_to post_path(@post)
   else
    flash[:notice] = "Discussion has not been created"
    redirect_to post_path(@post)
   end

 end

 # PATCH/PUT /discussions/1 or /discussions/1.json
 def update
  @discussion = @post.discussions.find(params[:id])

  respond_to do |format|
  if @discussion.update(discussion_params)
    format.html { redirect_to post_url(@post), notice: 'Discussion was successfully updated.' }
   else
    format.html { redirect_to post_url(@post), alert: 'Discussion was not updated.' }
   end
  end
 end

  # DELETE /discussions/1 or /discussions/1.json
  def destroy

   @discussion = @post.discussions.find(params[:id])
   @discussion.destroy
   redirect_to post_path(@post)
  end

 private
  # Use callbacks to share common setup or constraints between actions.
  def set_discussion
   @discussion = Discussion.find(params[:id])
  end


  # Only allow a list of trusted parameters through.
  def discussion_params
   params.require(:discussion).permit(:content)
 end
 end

我已经发送了ansys/formess/formes到：

<%= render "answers/form", post: @post, discussion: discussion, answer: discussion.answers.build %>

answers/_form.html.erb文件：

<%= form_with(model: [post, discussion, answer], class: "contents") do |form| %>

当我使用相同的代码时，我会得到“尚未创建答案”的警报。也就是说，它没有保存。 如何解决这个问题。我已经处理这个问题已经很长时间了。但是没有结果。

我的路由如果需要：

post_discussion_answers_path      GET      /posts/:post_id/discussions/:discussion_id/answers(.:format)                answers#index

                                  POST     /posts/:post_id/discussions/:discussion_id/answers(.:format)                answers#create

new_post_discussion_answer_path   GET      /posts/:post_id/discussions/:discussion_id/answers/new(.:format)            answers#new

edit_post_discussion_answer_path  GET      /posts/:post_id/discussions/:discussion_id/answers/:id/edit(.:format)       answers#edit

post_discussion_answer_path       GET      /posts/:post_id/discussions/:discussion_id/answers/:id(.:format)            answers#show

                                  PATCH    /posts/:post_id/discussions/:discussion_id/answers/:id(.:format)            answers#update

                                  PUT      /posts/:post_id/discussions/:discussion_id/answers/:id(.:format)            answers#update

                                  DELETE   /posts/:post_id/discussions/:discussion_id/answers/:id(.:format)            answers#destroy

post_discussions_path             GET      /posts/:post_id/discussions(.:format)  discussions#index

                                  POST     /posts/:post_id/discussions(.:format)  discussions#create

new_post_discussion_path          GET      /posts/:post_id/discussions/new(.:format)  discussions#new

edit_post_discussion_path         GET      /posts/:post_id/discussions/:id/edit(.:format)                discussions#edit

发布，讨论和答案模型：

class Post < ApplicationRecord
  belongs_to :user
  has_many :post_users, dependent: :destroy
  has_many :comments, dependent: :destroy
  has_many :tasks, dependent: :destroy
  has_many :discussions, dependent: :destroy
  has_many :answers, dependent: :destroy
  accepts_nested_attributes_for :tasks
  accepts_nested_attributes_for :discussions
end

class Discussion < ApplicationRecord
  belongs_to :post
  belongs_to :user
  has_many :answers, dependent: :destroy
end

class Answer < ApplicationRecord
  belongs_to :post
  belongs_to :user
  belongs_to :discussion
end