如何在Rails 3中使用Mongoid嵌入资源创建嵌套表单?

Question

我有一个Recipe模型，其中嵌入了成分，使用Mongoid。

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食谱，以及该食谱的相关成分，但我很难理解我该如何做到这一点。这是我目前所看到的:

_form.html。erb -用于Recipe视图

<%= 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

配料控制器

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

这将呈现新的成分表单，但是没有成分字段。谁能告诉我我哪里做错了吗?

Answer 1

显示嵌套表单时，尝试使用(注意等号):

<%= f.fields_for

而不是

<% f.fields_for

参见这个类似的问题

Answer 2

我最近遇到了一个非常类似的问题。我发现这个类似的问题张贴在Github上的蒙古问题跟踪器非常有帮助:

https://github.com/mongoid/mongoid/issues/1468 issuecomment - 6898898

这一行

= f.fields_for :ingredients do |builder|

应该像这样:

= f.fields_for @recipe.ingredients do |builder|