Question

我有3个嵌套模型：

class Recipe < ActiveRecord::Base
  has_many :recipe_ingredients
  has_many :ingredients, :through => :recipe_ingredients
  accepts_nested_attributes_for :ingredients
  accepts_nested_attributes_for :recipe_ingredients, :allow_destroy => true

  attr_accessible :description, :name, :preparation, :recipe_ingredients_attributes, :ingredients_attributes
  validates_presence_of :name, :description, :preparation
end

class RecipeIngredient < ActiveRecord::Base
  belongs_to :recipe, :foreign_key => "recipe_id"
  belongs_to :ingredient, :foreign_key => "ingredient_id"
  accepts_nested_attributes_for :ingredient
  delegate :name, :to => :ingredient, :allow_nil => true

  attr_accessible :ingredient_id, :quantity, :recipe_id, :ingredient_attributes
end

class Ingredient < ActiveRecord::Base
  has_many :recipe_ingredients
  has_many :recipes, :through => :recipe_ingredients

  attr_accessible :name
end

这是我的食谱控制器：

#<snip>
def new
  @recipe = Recipe.new

  respond_to do |format|
    format.html # new.html.erb
    format.json { render json: @recipe }
  end
end

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

  respond_to do |format|
    if @recipe.save
      format.html { redirect_to @recipe, notice: 'Het recept werd aangemaakt.' }
      format.json { render json: @recipe, status: :created, location: @recipe }
    else
      format.html { render action: "new" }
      format.json { render json: @recipe.errors, status: :unprocessable_entity }
    end
  end
end
#</snip>

这就是我的表单（使用simple_forms和nested_forms gems）：

= simple_nested_form_for @recipe, :html => { :class => 'form-horizontal' } do |f|
  = f.input :name, :label => "Naam"
  = f.input :description, :input_html => { :class => "span6" }, :label => "Beschrijving"
  = f.input :preparation, :input_html => { :class => "span6" }, :label => "Bereiding"

  = f.simple_fields_for :recipe_ingredients do |ri|
    = ri.input :quantity, :label => "#"
    = ri.input :name, :label => "Ingredient"
    = ri.link_to_remove "ingredient verwijderen"
  %p
    = f.link_to_add "Voeg ingredient toe", :recipe_ingredients

  .form-actions
    = f.submit "Update recept", :class => 'btn btn-primary'
    = link_to t('.cancel', :default => "Annuleer"), recipes_path, :class => 'btn'

每当我保存食谱时，它都会给我： RecipesController #create中的ActiveModel :: MassAssignmentSecurity :: Error 无法批量分配受保护的属性：名称

这是我的堆栈跟踪：

Started POST "/recipes" for 127.0.0.1 at 2012-12-15 19:14:38 +0100
Processing by RecipesController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"72F9E5Cim3SFlFabViy8p4eF4el+RGtdlPmkuaoBU90=", "recipe"=>{"name"=>"tets", "description"=>"egwrb", "preparation"=>"gwrv", "recipe_ingredients_attributes"=>{"1355595249889"=>{"quantity"=>"21", "name"=>"grsd", "_destroy"=>"false"}}}, "commit"=>"Update recept"}
  User Load (0.4ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 1 LIMIT 1
Completed 500 Internal Server Error in 2ms

ActiveModel::MassAssignmentSecurity::Error (Can't mass-assign protected attributes: name):
  app/controllers/recipes_controller.rb:54:in `new'
  app/controllers/recipes_controller.rb:54:in `create'

我尝试过单数/复数但没有运气。我不知道我做错了什么。：ingredient_attributes应该是可访问的，但似乎不是？

亲切的问候，史蒂芬

Answer 1

实际上，我认为你的观点中只有一个小错字：

= f.simple_fields_for :ingredient do |i|

应该是

= ri.simple_fields_for :ingredient do |i|

我注意到，当它应该嵌套在recipe_ingredients_attributes下时，params hash在顶层有成分。（您可能还需要在accepts_nested_attributes_for）上设置RecipeIngredient

Answer 2

您必须创建一组额外的嵌套字段。在ri区块内，您需要添加

- ri.simple_fields_for :ingredient do |i|
  = i.input :name

通过这样做，您可以正确设置ingredient的名称，而不是recipe_ingredient。

无法使用嵌套模型批量分配受保护的属性

2 个答案: