我有一个双嵌套表格，我需要在孩子记录中保存其中一位父母的ID。但是，父记录可能还没有ID，因此我无法保存ID。如何传递这个参考ID？谢谢！
我对Rails还是陌生的，正在开发一个家庭作业应用程序，老师可以创建一个Work。 Work可以具有Questions，而Question可以具有Answers。
对于Work，学生可以创建Submission。 Submission可以有Answers（这是对Work的问题的答复。
目标，最终，我想显示学生提交的信息，包括相关的Work信息，Answers与{{1} }他们正在回答。
我目前无法创建Question并使其引用嵌套的Answer的ID（这对我来说很有意义，因为在提交表单时，Question可能不存在，并且没有ID。
我的问题是：
Question传递到question_id中？models / work.rb
answermodels / submission.rb
class Work < ApplicationRecord
has_many :submissions
has_many :questions # Allow for quizzes
accepts_nested_attributes_for :questions, reject_if: :all_blank, allow_destroy: true
end
# == Schema Information
#
# Table name: works
#
# id :bigint(8) not null, primary key
# description :text
# due_date :datetime
# name :string
# submittable :boolean default(TRUE)
# url :string
# created_at :datetime not null
# updated_at :datetime not null
# course_id :integer
#
models / question.rb
class Submission < ApplicationRecord
belongs_to :work
has_many :answers, as: :answerable
accepts_nested_attributes_for :answers, reject_if: :all_blank, allow_destroy: true
end
# == Schema Information
#
# Table name: submissions
#
# id :bigint(8) not null, primary key
# enrollment_id :integer
# work_id :integer
# title :string
# content :text
# created_at :datetime not null
# updated_at :datetime not null
#
models / answer.rb
class Question < ApplicationRecord
belongs_to :work
has_many :answers, as: :answerable
# has_many :answers, as: :answerable, inverse_of: :question
accepts_nested_attributes_for :answers, reject_if: :all_blank, allow_destroy: true
validates :value, presence: true, allow_nil: false
end
# == Schema Information
#
# Table name: questions
#
# id :bigint(8) not null, primary key
# value :string
# created_at :datetime not null
# updated_at :datetime not null
# work_id :bigint(8)
#
# Indexes
#
# index_questions_on_work_id (work_id)
#
controller / works_controller.rb
class Answer < ApplicationRecord
belongs_to :answerable, polymorphic: true
validates :value, presence: true, allow_nil: false
end
# == Schema Information
#
# Table name: answers
#
# id :bigint(8) not null, primary key
# answerable_type :string
# is_canon :boolean default(FALSE)
# is_correct :boolean default(FALSE)
# value :string
# created_at :datetime not null
# updated_at :datetime not null
# answerable_id :bigint(8)
# question_id :bigint(8)
#
# Indexes
#
# index_answers_on_answerable_id (answerable_id)
# index_answers_on_question_id (question_id)
#
# Foreign Keys
#
# fk_rails_... (question_id => questions.id)
#
_form.html.slim
class WorksController < ApplicationController
def create
@work = Work.new(work_params)
respond_to do |format|
if @work.save
format.html { redirect_to @work, notice: 'Work was successfully created.' }
format.json { render :show, status: :created, location: @work }
else
format.html { render :new }
format.json { render json: @work.errors, status: :unprocessable_entity }
end
end
end
private
def work_params
params.require(:work).permit(:name, :category_id, :course_id, :description, :url, :due_date, :published, :points, :grades_published,
questions_attributes: [:id, :value, :_destroy,
answers_attributes: [:id, :value, :question_id, :is_correct, :is_canon, :_destroy]
]
)
end
end
_question_fields.html.slim
...
/ Questions
.form-group.u-mt2x
= form.fields_for :questions do |question|
= render 'shared/question_fields', f: question
.links
= link_to_add_association 'Add Question', form, :questions, class: "u-button--New u-button--sm", partial: 'shared/question_fields'
_answer_fields.html.slim
.nested-fields
.form-group
.form-group
= f.label :value, "Question", :class => "required"
= link_to_remove_association "remove question", f, data: {confirm: 'Are you sure you want to remove this question?'}
= f.text_field :value, class: "form-control"
// Answers / Choices
.form-group.u-mt2x
= f.fields_for :answers do |answer|
= render 'shared/answer_fields', f: answer
.links
= link_to_add_association 'Add Choice', f, :answers, partial: "shared/answer_fields"
routes.rb
.nested-fields
.form-group
.form-group
= f.label :value, "Answer Choice", :class => "required"
= link_to_remove_association "remove choice", f, data: {confirm: 'Are you sure you want to remove this answer?'}
= f.text_field :value, class: "form-control"
.form-group
= f.label :is_correct, "This is the correct answer"
div
= f.label :is_correct, "Yes", value: true
= f.radio_button :is_correct, true
= f.label :is_correct, "No", value: false
= f.radio_button :is_correct, false
/= f.select :is_correct, options_for_select([["Yes", true], ["No", false]])
// Hidden fields
.form-group
- if current_user.id == @work.course.owner.id
= f.label :is_canon, "Canonical Choice"
= f.hidden_field :is_canon, value: current_user.id == @work.course.owner.id, :readonly => true
/.form-group
- if current_user.id == @work.course.owner.id
= f.label :question_id, "Question ID"
= f.text_field :question_id, @question.id
Rails.application.routes.draw do
resources :submissions
...
devise_for :users, :path => 'auth', :controllers => {:registrations => "registrations"}
get "works/index"
resources :works do
member do
put 'toggle_publish'
put 'toggle_publish_grades'
end
end
...
root 'home#index'
end
模型中添加inverse_of给了我Question，此外，ArgumentError (When assigning attributes, you must pass a hash as an argument.)似乎不适用于inverse_of模型关系。polymorphic我还考虑过分离表单，使得class Question < ApplicationRecord
...
has_many :answers, as: :answerable, inverse_of: :question
...
end
/ Question不是在表单提交时创建的，而是在AJAX请求中创建的，以便我可以获取{{1} }。
在提交表单时，呼叫Answer（呼叫question_id）并让每个成员创建自己的记录，而不是在questions_controller
我有一个双嵌套表格，我需要在孩子记录中保存其中一位父母的ID。但是，父记录可能还没有ID，因此我无法保存ID。如何传递这个参考ID？谢谢！