Rails以相反的顺序嵌套资源参数

Question

我花了一段时间尝试调试此行为，但未成功，因此我希望帮助找出为什么我的嵌套资源参数似乎以错误的顺序包含在 URL 中。出于某种原因，可以为课程添加和删除课程，但编辑课程会崩溃，因为 ActiveRecord 尝试使用课程 ID 查找课程，反之亦然。

课程和课程模型

class Course < ApplicationRecord
  has_many :lessons, dependent: :destroy

  extend FriendlyId
  friendly_id :title, use: :slugged

class Lesson < ApplicationRecord
  belongs_to :course

  extend FriendlyId
  friendly_id :title, use: :slugged

课程控制器

class LessonsController < ApplicationController
  before_action :set_lesson, only: [:show, :edit, :update, :destroy ]
  
  def index
    @lessons = Lesson.all
  end

  def show
  end

  def new
    @lesson = Lesson.new
    @course = Course.friendly.find(params[:course_id])
    authorize @lesson
  end

  def edit
    authorize @lesson
  end

  def create
    @lesson = Lesson.new(lesson_params)
    @course = Course.friendly.find(params[:course_id])
    @lesson.course_id = @course.id

    if @lesson.save
      redirect_to course_lesson_path(@course, @lesson), notice: "Lesson was successfully created."
    else
      render :new, status: :unprocessable_entity
    end
  end

  def update
    authorize @lesson
    if @lesson.update(lesson_params)
      redirect_to course_lesson_path(@course, @lesson), notice: "Lesson was successfully updated."
    else
      render :edit
    end
  end

  def destroy
    authorize @lesson
    @lesson.destroy
    redirect_to course_path(@course), notice: "Lesson was successfully destroyed."
  end

  private
    def set_lesson
      @course = Course.friendly.find(params[:course_id])
      @lesson = Lesson.friendly.find(params[:id])
    end

    def lesson_params
      params.require(:lesson).permit(:title, :content, :course_id)
    end
end

路线

  resources :courses do
    resources :lessons
  end

当我做 Rails 路线时会出现什么：

edit_course_lesson GET /courses/:course_id/lessons/:id/edit(.:format)

但是，当我实际编辑课程时，参数似乎会切换，从而导致崩溃。请参阅下面的示例，它认为第四课是课程。

网址：/courses/fourth-lesson/lessons/forensic-science-344/edit

ActiveRecord::RecordNotFound in LessonsController#edit
can't find record with friendly id: "fourth-lesson"
              
  private
    def set_lesson
      @course = Course.friendly.find(params[:course_id]) <- Crashes on this line
      @lesson = Lesson.friendly.find(params[:id])
    end

更新：这是编辑课程的表格。

.container
  = simple_form_for([@course, @lesson]) do |f|
    = f.error_notification
    = f.error_notification message: f.object.errors[:base].to_sentence if f.object.errors[:base].present?
  
    .form-inputs
      = f.input :title
      = f.input :content
      %small
      = f.error :content, class: 'text-danger'
  
    .form-actions
      = f.button :submit, class: 'btn btn-primary my-4'

Answer 1

原来我没有在编辑链接上传入 course 参数。我有link_to 'Edit', edit_course_lesson_path(lesson)。

应该是edit_course_lesson_path(@course, lesson)。

感谢大家的耐心等待，非常感谢 Deepesh 终于让我想到了查看编辑链接。