嵌套表单不会保存，Rails 4

Question

我无法弄清楚我做错了什么，但我的嵌套表格不会保存到我的房间桌子上。

这是我的观点

new.html.erb

<h1>Room Assignments</h1>
<p>

<%= form_for @member do |f| %>
  <%= f.label :name, "Member name" %><br>
  <%= f.text_area :name %><br>`enter code here`

  <%= f.fields_for :room do |b| %>
    <%= b.label :room_name %><br>
    <%= b.text_area :room_name %><br>
    <%= b.label :rent %><br>
    <%= b.text_area :rent %><br>

  <% end %>

  <%= f.submit "Submit" %>
<% end %>

members_controller.rb

class MembersController < ApplicationController
  def new
    @member = Member.new
    @member.purchases.build

    @room = @member.build_room
  end

  def index
    @member = Member.all
  end

  def create
    @member = Member.create(member_params)
    @room = @member.create_room
    if @member.save
        redirect_to new_purchase_url
    else
        render :new
    end
  end

  def show
    @member = Member.find(params[:id])
  end

  def member_params
    params.require(:member).permit(:name, :room_id,
                                    room_attributes: [:rent, :name, :id, :member_id],
                                    purchase_attributes: [:description, :cost, :id, :member_id])
  end
end

member.rb

class Member < ActiveRecord::Base
  belongs_to :room
  has_many :purchases

  accepts_nested_attributes_for :purchases, :room
end

room.rb

class Room < ActiveRecord::Base
  has_one :member, foreign_key: "member_id"
  has_many :purchases 
end

当我检查它是否已保存时，这是在rails控制台中输出的内容：

2.0.0-p451 :070 > Member.last
  Member Load (0.3ms)  SELECT  "members".* FROM "members"  ORDER BY     "members"."id" DESC LIMIT 1
 => #<Member id: 24, name: "Tom", room_id: 38> 
2.0.0-p451 :071 > Room.last
  Room Load (0.3ms)  SELECT  "rooms".* FROM "rooms"  ORDER BY "rooms"."id" DESC LIMIT 1
 => #<Room id: 38, room_name: nil, rent: nil, member_id: nil> 

Answer 1

问题是您在创建操作中调用了@room = @member.create_room。前一行应该已经拉入参数并构建了成员和房间实例。因此，当您致电create_room时，您实际上正在更换添加了新（空白）房间的房间。这就是我要做的事情：

def create
  @member = Member.new(member_params)
  if @member.save
    redirect_to new_purchase_url
  else
    render :new
  end
end