accepts_nested_attributes_for对于has_one关系不起作用

Question

我在has_one关系中遇到accepts_nested_attributes_for时遇到问题.

模特:购买和销售.

class Purchase < ActiveRecord::Base 
  has_one :sale, :dependent => :destroy
  accepts_nested_attributes_for :sale
end

class Sale < ActiveRecord::Base  
  belongs_to :purchase
end

在控制器/新动作中:

@purchase = Purchase.new(
  :club_id => @club.id,
  :subcategory_id => subcategory.id
)

在视图(HAML)中:

- form_for(@purchase) do |f|
  # some fields for purchase
  - f.fields_for :sale do |s|
    = s.text_field :amount, :size => 6
    # and so on

问题:这实际上并没有在我的视图中呈现任何待售的输入框.购买字段呈现正常,但销售字段不会出现.

如果我将此行添加到控制器:

@purchase.sale.build

我收到此错误:

class Purchase < ActiveRecord::Base 
  has_many :sales, :dependent => :destroy
  accepts_nested_attributes_for :sales
end

为了使事情变得更奇怪,如果我将关联类型更改为has_many而不是has_one,从而创建:

class Purchase < ActiveRecord::Base 
  has_one :sale, :dependent => :destroy
  accepts_nested_attributes_for :sale
end

class Sale < ActiveRecord::Base  
  belongs_to :purchase
end

一切都开始正常工作 - 销售字段开始出现在我的视图中,@ purchase.sales.build不会返回错误,依此类推.当然,这对我没有帮助,因为它应该是has_many,而不是has_one.

任何人都可以对这种情况有所了解吗？

Answer 1

has_one构建与has_many不同

@purchase.build_sale

请参阅有关has_one的文档http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#M001834

帐户#build_beneficiary(类似于Beneficiary.new("account_id"=> id))