Rails form_for嵌套表单未创建/保存

Question

这是我的型号：

class Drama < ApplicationRecord
has_many :reviews 
has_many :users, :through => :reviews
validates :name, uniqueness: true 
accepts_nested_attributes_for :reviews
accepts_nested_attributes_for :users 

结束

class Review < ApplicationRecord
belongs_to :user 
belongs_to :drama 

结束

类用户<应用程序记录has_many：评论has_many：戏剧，：through=>：评论验证：用户名，唯一性：true，存在性：true验证：电子邮件，唯一性：true，存在性：truehas_secure_password结束

这是一个没有保存/创建的嵌套表单！

<div>
<%= form_for @drama do |f| %>
<h2>Drama Info</h2>
<strong>Name: <%= f.text_field :name %></strong><br>
<strong>Genre: <%= f.text_field :genre %></strong><br>

<h2>Review Info</h2>
<%= f.fields_for :reviews, @drama.reviews.build do |r| %>
<%= r.label :title %>
<%= r.text_field :title %><br>
<%= r.label :rating %>
<%= r.number_field :rating %><br>
<%= r.label :content %>
<%= r.text_area :content %><br>
<%end%>
<%= f.submit %>
<%end%>
</div>

以下是我的路线：

Rails.application.routes.draw do
resources :dramas do
resources :reviews, only: [:new, :show]
end
resources :dramas 
resources :users
resources :reviews 
get '/auth/facebook/callback', to: 'sessions#create_with_fb'
get '/', to: 'sessions#home'
get '/signup', to: 'users#new'
post '/signup', to: 'users#create'
get '/login', to: 'sessions#new'
post '/login', to: 'sessions#create'
post '/logout', to: 'sessions#destroy'
# For details on the DSL available within this file, see https://guides.rubyonrails.org/routing.html
end

这是我的戏剧控制器：

class DramasController < ApplicationController
before_action :find_by_drama, only: [:edit, :update, :destroy, :show]
before_action :current_user, only: [:create, :update, :edit, :destroy]
def index 
@dramas = Drama.all 
end 
def new    
@drama = Drama.new 
@drama.reviews.build 
end  

def show 
session[:drama_id] = @drama.id
# @drama = Drama.find(session[:drama_id])
end 
def create 
@drama = Drama.new(drama_params)
if @drama.save 
redirect_to dramas_path
else 
render :new 
end 

结束

def update 
@drama = Drama.update(drama_params)
redirect_to dramas_path 
end 
def edit 
end 
def destroy 
@drama.destroy 
redirect_to dramas_path 
end 

private 
def drama_params
params.require(:drama).permit(
:name,
:genre,
reviews_attributes: [
:title,
:rating,
:content
]
)
end 

结束

我的数据库。架构：

ActiveRecord::Schema.define(version: 2020_12_19_073757) do
create_table "dramas", force: :cascade do |t|
t.string "name"
t.string "genre"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
end
create_table "reviews", force: :cascade do |t|
t.integer "user_id"
t.integer "drama_id"
t.string "title"
t.text "content"
t.integer "rating"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
end
create_table "users", force: :cascade do |t|
t.string "username"
t.string "email"
t.string "password_digest"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
end
end

请帮忙！被卡住

Answer 1

不需要fields_for中的@drama.reviews.build部分，因为您已经在new操作中构建了评审。试着移除它，看看它是否有效。然后在edit操作中添加@drama.reviews.build，如果您也想在该操作中构建另一个审阅。在视图中构建嵌套属性可能会导致一些怪异的行为。如果仍然不起作用，请从正在运行的应用程序发布跟踪，或者在视图中尝试@drama.errors.inspect，或者使用puts在服务器日志中打印错误。