Question

以下是模型。

Recipes::Recipe：

module Recipes
  class Recipe < ActiveRecord::Base
    include ApplicationHelper

    attr_accessible :body, :title, :author, :photos, :tags

    has_many :photos
    has_many :favorites
    has_many :taggings
    has_many :tags, :through => :taggings

    belongs_to :author,
               :class_name => :User,
               :foreign_key => :author_id

    has_many :favorers,
             :source => :user,
             :through => :favorites

    before_create :default_values
    before_validation :create_slug

    validates_presence_of :title, :body, :author
    validates_uniqueness_of :title, :slug
  end
end

User：

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  attr_accessible :login, :email, :password, :password_confirmation, :remember_me

  has_many :recipes,
           :class_name => 'Recipes::Recipe',
           :foreign_key => :author_id

  has_many :favorite_recipes,
           :class_name => 'Recipes::Recipe',
           :foreign_key => :recipe_id,
           :source => :recipe,
           :through => :favorites

  end
end

Recipes::Favorite：

module Recipes
  class Favorite < ActiveRecord::Base
    attr_accessible :user_id, :recipe_id

    belongs_to :recipe,
               :class_name => "Recipes::Recipe"
    belongs_to :user,
               :class_name => "User"
  end
end

当引用Recipes::Recipe模型上的属性时，关联起作用。如果我recipe = Recipes::Recipe.first; recipe.favorers它可行。当我user = User.first; user.favorite_recipes时收到错误。

错误：

1.9.3-p392 :002 > u.favorite_recipes
ActiveRecord::HasManyThroughAssociationNotFoundError: Could not find the association     
:favorites in model User

我认为它正在尝试找到模型Favorite，但实际上它应该是Recipes::Favorite。我在Rails文档中读到:foreign_key和:class_name在has_many :through关联中被忽略，但我仍尝试过它们，但它仍然无效。所以现在我想知道，我怎么能告诉has_many :through的{{1}}参数它应该寻找命名空间模型？我还为:source参数尝试了:recipes_recipe，而:source的表名只是“收藏夹”。

Answer 1

我发现了问题。

解决方案出错了。

ActiveRecord::HasManyThroughAssociationNotFoundError: Could not find the association :favorites in model User

has_many :through关联正在has_many :favorites型号上寻找User。

所以，我刚刚添加了has_many :favorites, :class_name => 'Recipes::Favorite'，上面的代码开始为两个协会工作。

如何在has_many上使用：source参数：通过与命名空间模型的关联？

1 个答案: