ruby-on-rails – 如何在Rails 3中使用Mongoid嵌入式资源创建嵌

class Recipe
  include Mongoid::Document
  include Mongoid::Timestamps

  field :title,:type => String
  embeds_many :ingredients

  accepts_nested_attributes_for :ingredients,:reject_if => lambda { |a| a[:title].blank? },:allow_destroy => true

  validates :title,:presence => true
end

class Ingredient
  include Mongoid::Document
  field :name,:type => String
  field :quantity,:type => String

  embedded_in :recipe,:inverse_of => :ingredients
end

我希望能够同时创建一个新配方,以及该食谱的相关成分,但我很难理解我将如何做到这一点.这是我到目前为止：

_form.html.erb – 在配方视图中使用

<%= form_for @recipe do |f| %>  
...
  <li>Title: <%= f.text_field :title %></li>

  <% f.fields_for :ingredients do |builder| %>
    <%= render "ingredient_fields",:f => builder %>
  <% end %>
...
<%= f.submit %>

_ingredient_fields.html.erb

<%= f.text_field :name %>

配方控制器

def new
  @recipe = Recipe.new
  @ingredient = @recipe.ingredients.build
end

def create
  @recipe = Recipe.new(params[:recipe])


  if @recipe.save
    redirect_to @recipe,notice: 'Recipe was successfully created.'
  else
    render action: "new"
  end
end

成分控制器

def new
  @recipe = Recipe.find(params[:recipe_id])
  @ingredient = @recipe.ingredients.build
end

def create
  @recipe = Recipe.find(params[:recipe_id]) 
  @ingredient = @recipe.ingredients.build(params[:ingredient]) 
  # if @recipe.save 
end

这使得新成分形成,但成分没有领域.谁能给我任何关于我做错的指示？