具有多对多通过关系的嵌套模型形成“无法分配质量属性”错误

Question

我的表单出现错误“无法批量分配受保护的属性：用户”。我有一个用户通过一个表单创建一个家庭和其他用户。目前我正在尝试创建让用户以一种形式创建一个新家庭和一个新用户的功能。我安装了 Cocoon gem 并且正在使用 Rails 3.2.16。 https://github.com/nathanvda/cocoon

此行出现错误

family_controller.rb

  def create
    binding.pry
    @user = current_user
    @family = Family.new(params[:family]) <<<<<

参数是：

=> {"utf8"=>"✓",
 "authenticity_token"=>"EqWGxK3Fuj2uYk3namWK9SbXLPRKSn6cReT7wQddG0E=",
 "family"=>
  {"name"=>"test Family",
   "users_attributes"=>{"0"=>{"first_name"=>"jane", "last_name"=>"smith"}}},
 "commit"=>"Create Family",
 "action"=>"create",
 "controller"=>"families"}

型号

user.rb

class User < ActiveRecord::Base

  attr_accessible :first_name, :last_name, :age_months, :height_inches, :weight_ounces

  has_many :user_families
  has_many :families, through: :user_families
end

family.rb

class Family < ActiveRecord::Base
   attr_accessible :location, :name, :users_attributes, user_families_attributes

   has_many :user_families
   has_many :users, through: :user_families

   accepts_nested_attributes_for :users, :reject_if => :all_blank, :allow_destroy => true
   accepts_nested_attributes_for :user_families, :reject_if => :all_blank, :allow_destroy => true
end

查看

families.new.html.erb

<%= form_for(@family) do |f| %>

<form class = 'form-horizontal' role = 'form'>
  <div class='form-group'>
    <%= f.label :name %>
    <%= f.text_field :name, placeholder: 'Family Name' %>
  </div>
  <div class='form-group'>
  <%= f.fields_for @new_user do |ff| %>
    <%= label_tag :first_name %>
    <%= ff.text_field :first_name, placeholder: 'First Name' %>
    <%= label_tag :last_name %>
    <%= ff.text_field :last_name, placeholder: 'Last Name' %>
    <%= label_tag :age_months %>
    <%= ff.number_field :age_months, placeholder: 'Enter Age' %>
    <%= label_tag :height_inches %>
    <%= ff.number_field :height_inches, placeholder: 'Height in Inches' %>
    <%= label_tag :weight_ounces %>
    <%= ff.number_field :weight_ounces, placeholder: 'Weight in Pounds' %>
  <% end %>
  </div>
  <div class='actions'>
    <%= f.submit %>
  </div>
</form>
<% end %>

控制器

family_controller.rb

class FamiliesController < ApplicationController
  def index
    @families = Family.all
  end

  def show
    @user = current_user
    @family = Family.find(params[:id])
  end

  def new
    @user = current_user
    @family = Family.new(name: "#{@user.last_name} Family")
    @family.users.build
    @new_user = User.new
  end

  def edit
    @family = Family.find(params[:id])
  end

  def create
    @user = current_user
    @family = Family.new(params[:family])
    @family.users << @user
    @family.save
    redirect_to root_path
  end

  def update
    @family = Family.find(params[:id])
    @family.update_attributes(params[:family])
    @family.save
    redirect_to root_path(anchor: 'profile')
  end

  def destroy
    @family = Family.find(params[:id])
    @family.destroy
    redirect_to families_path
  end
end

Answer 1

Family 和 User 关联一维关系。

在你看来families/new.html.erb

改变

<%= f.fields_for @new_user do |ff| %>

到

<%= f.fields_for :users, @new_user do |ff| %>