Question

我正在按照本教程http://railscasts.com/episodes/196-nested-model-form-part-1了解嵌套表单。

我有3个模型第一个 user.rb ：

class User
 has_many :boards, dependent: :destroy
 has_many :posts, dependent: :destroy, :autosave => true
 accepts_nested_attributes_for :boards
 accepts_nested_attributes_for :posts

end

第二个模型是 board.rb

class Board
has_many :posts, :dependent => :destroy , :autosave => true
accepts_nested_attributes_for :posts
belongs_to :user
end

第三个模型是 post.rb

class Post
belongs_to :user
belongs_to :board
end

我想创建一个新帖子，因为我已经在 boards_controller.rb

def new
  @board = Board.new
  @board.posts.build
 respond_to do |format|
  format.html # new.html.erb
  format.json { render json: @board }
 end
end

def create
 @board = current_user.boards.new(params[:board])
 @board.user = current_user
respond_to do |format|
  if @board.save
    format.html { redirect_to @board, notice: 'Board was successfully created.' }
    format.json { render json: @board, status: :created, location: @board }
  else
    format.html { render action: "new" }
    format.json { render json: @board.errors, status: :unprocessable_entity }
  end
end
end

通过这2种方法，我在视图中获得帖子的每个属性。在我的控制台中，如果我在创建一个主板之后添加 Post.first 我得到：

1.9.2-p290 :007 > Post.first
=> #<Post _id: 4f0b0b211d41c80d08002afe, _type: nil, created_at: 2012-01-09 15:43:29 UTC, user_id: nil, board_id: BSON::ObjectId('4f0b0b1b1d41c80d08002afd'), content: "hello post 2">

但如果你看看我得到 user_id：nil 。

在普通模型中，我获得用户ID，例如在控制器的创建操作中，我将 @ post.user = current_user.id或@ post.user = current_user

如何从嵌套表单中获取嵌套模型中的user_id？

Answer 1

def create
 @board = current_user.boards.new(params[:board])
 #@board.user = current_user - you don't need this line, since you create new board record using current_user object
 # assign current_user id to the each post.user_id
@board.posts.each {|post| post.user_id = current_user}

respond_to do |format|
   if @board.save
     format.html { redirect_to @board, notice: 'Board was successfully created.' }
     format.json { render json: @board, status: :created, location: @board }
   else
    format.html { render action: "new" }
    format.json { render json: @board.errors, status: :unprocessable_entity }
   end
 end
end

Answer 2

您应该只需设置user_id属性。

在您的代码中，您将current_user对象分配给关联。

这应该有效：

def create
 @board = current_user.boards.new(params[:board])
 @board.user_id = current_user.id
respond_to do |format|
  if @board.save
    format.html { redirect_to @board, notice: 'Board was successfully created.' }
    format.json { render json: @board, status: :created, location: @board }
  else
    format.html { render action: "new" }
    format.json { render json: @board.errors, status: :unprocessable_entity }
  end
end
end

get user_id设计嵌套表单rails 3.1

2 个答案: