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我有以下设置：

架构.rb

ActiveRecord::Schema.define(version: 20130923235150) do

  create_table "addresses", force: true do |t|
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "user_addresses", force: true do |t|
    t.integer  "user_id"
    t.integer  "address_id"
    t.string   "purpose"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "users", force: true do |t|
    t.datetime "created_at"
    t.datetime "updated_at"
  end

end

用户.rb：

class User < ActiveRecord::Base
  has_one :user_address
  has_one :primary_shipping_address, through: :user_address, class_name: :UserAddress, source: :address
  has_one :primary_billing_address,  through: :user_address, class_name: :UserAddress, source: :address
end

地址.rb:

class Address < ActiveRecord::Base
  has_one :user_address
  has_one :primary_shipping_user, through: :user_address, class_name: :UserAddress, source: :user
  has_one :primary_billing_user,  through: :user_address, class_name: :UserAddress, source: :user
end

用户地址.rb：

class UserAddress < ActiveRecord::Base
  belongs_to :user
  belongs_to :address
end

当有人这样做时user.primary_billing_address = address，我希望连接模型实例将“计费”设置为其目的。与运输和“运输”类似。前任。

irb(main):013:0> u = User.new
=> #<User id: nil, created_at: nil, updated_at: nil>
irb(main):014:0> a = Address.create
=> #<Address id: 3, created_at: "2013-09-24 00:13:07", updated_at: "2013-09-24 00:13:07">
irb(main):015:0> u.primary_billing_address = a
=> #<Address id: 3, created_at: "2013-09-24 00:13:07", updated_at: "2013-09-24 00:13:07">
irb(main):016:0> u.save!
=> true
irb(main):017:0> u.user_address
=> #<UserAddress id: 2, user_id: 3, address_id: 3, purpose: nil, created_at: "2013-09-24 00:13:18", updated_at: "2013-09-24 00:13:18">
(not what I want... purpose should be "billing")

我怎样才能做到这一点，以便它适用于新的和持久的记录？我已经提出了 90% 的解决方案，但是由于我的方法没有捕捉到的边缘情况而打破了一些随机规范。

要解决的最棘手的部分是association=行为方式：在新记录上，它将关联排队以通过连接模型进行分配。

PS：我省略了has_one用于获取我想要的地址的关系的条件。我认为这个问题与此无关。

4

1 回答 1

1

首先，关联有点偏离，两者都primary_shipping_address将primary_billing_address返回相同的地址。您可以将其更改为

class User < ActiveRecord::Base
  has_many :user_addresses # user can have multiple addresses one for shipping and one for billing
  has_one :primary_shipping_address,
           through: :user_address, class_name: :UserAddress, 
           source: :address, :conditions => ['user_addresses.purpose = ?','shipping']

  has_one :primary_billing_address, 
          through: :user_address, class_name: :UserAddress, 
          source: :address, :conditions => ['user_addresses.purpose = ?','billing']
end

要在保存地址的同时保存目的，有两种选择。

选项 1：覆盖默认association=方法

   # alias is needed to refer to original method
   alias_method :orig_primary_billing_address=, :primary_billing_address=
   def primary_billing_address=(obj)
     self.orig_primary_billing_address = obj
     self.user_addresses.where("address_id = ?", obj.id).update_attribute(:purpose, 'billing')  
   end

  # repeat for shipping

选项 2：创建一个自定义方法（我更喜欢这个，因为它更干净、更干燥）

   def save_address_with_purpose(obj,purpose)
      self.send("primary_#{purpose}_address=", obj)
      self.user_addresses.where("address_id = ?", obj.id).update_attribute(:purpose, purpose)  
   end
于 2013-09-24T01:40:19.187 回答