Rails的錯誤：accepts_nested_attributes_for沒有更新我的has_many協會

Question

我有2種型號：

class Book < ActiveRecord::Base 
    has_many :book_versions 
    accepts_nested_attributes_for :book_versions, allow_destroy: true 
    validates_associated :book_versions 

class BookVersion < ActiveRecord::Base 
    has_many :collection_items 
    has_many :collections, through: :collection_items 
    belongs_to :book 
    validates_presence_of :price, :isbn #<-- validates presence 

這裏是我的PARAMS。請注意，我如何將book_version的price的名稱保留爲bb空白。這應該是在BookVersion模型中的validates_presence_of :price驗證觸發（但它不）：

「book」=> {「title」=>「zzzzzz」，「subtitle」=>「」，「author_ids」 => [「」]，「illustrator_ids」=> [「」]，「award_ids」=> [「」]，「theme_ids」=> [「」]，「publication_date」=>「」，「imprint_id」=> 「1」，「language_ids」=> [「」]，「eng_vers_id」=>「」，「book_versions_attributes」=> {「0」=> {「book_id」=>「2848」，「name」=>「alt 「，」isbn「=>」「，」price「=>」「，」famis_number「=>」「，」famis_price「=>」「，」weight_in_pounds「=>」「}，」1「=> book_id「=>」2848「，」name「=>」bb「，」isbn「=>」123123123123「，」price「=>」「，」famis_number「=>」「，」famis_price「=>」「 「weight_in_pounds」=>「1.0」，「inventory」=>「08」，「id」=>「1030」}，

當我在我的控制器中做@book.update_attributes(params[:book])時，沒有任何一個book_versions更新即使一切似乎都有效：

>> @book.update_attributes(params[:book]) 
    => true 
    >> @book.book_versions 
    => [#<BookVersion id: 1030, book_id: 2848, name: "bb", isbn: "123123123123", inventory: "08", price: #<BigDecimal:7fc484885b80,'0.1122E2',18(18)>, famis_price: nil, famis_number: "", weight_in_pounds: #<BigDecimal:7fc4848861c0,'0.1E1',9(18)>, width: nil, height: nil, thickness: nil>, #<BookVersion id: 1031, book_id: 2848, name: "lb", isbn: "12312333333", inventory: "02", price: #<BigDecimal:7fc484886670,'0.2244E2',18(18)>, famis_price: nil, famis_number: "", weight_in_pounds: #<BigDecimal:7fc484886760,'0.1E1',9(18)>, width: nil, height: nil, thickness: nil>, #<BookVersion id: 1032, book_id: 2848, name: "hc", isbn: "111213213131", inventory: nil, price: #<BigDecimal:7fc4848869e0,'0.1212E4',9(18)>, famis_price: nil, famis_number: "", weight_in_pounds: #<BigDecimal:7fc484886d28,'0.1E1',9(18)>, width: nil, height: nil, thickness: nil>] 
    >> @book.book_versions.map(&:price) 
    => [#<BigDecimal:7fc484885b80,'0.1122E2',18(18)>, #<BigDecimal:7fc484886670,'0.2244E2',18(18)>, #<BigDecimal:7fc4848869e0,'0.1212E4',9(18)>] 
    >> @book.book_versions.map(&:price).map(&:to_f) 
    => [11.22, 22.44, 1212.0] 
    >> @book.save 
    => true 
    >> @book.book_versions.map(&:price).map(&:to_f) 
    => [11.22, 22.44, 1212.0] #<-- one of these should be `nil`. 

發生了什麼事？當我創建一個Book與許多BookVersion s形式工作完全正常。但是，當我使用現有書籍版本更新現有書籍時，它不會更新或驗證任何內容。

這是我的問題在這裏的延續：ActiveRecord: validates_associated does not work when updating model?

UPDATE ====

呃......我認爲這是在軌道中的錯誤？看看會發生什麼：

>> @book.update_attributes(params[:book]) 
    => true 
    >> @book.book_versions 
    => [#<BookVersion id: 1030, book_id: 2848, name: "bb", isbn: "123123123123", inventory: "08", price: #<BigDecimal:7fc487ee9488,'0.1122E2',18(18)>, famis_price: nil, famis_number: "", weight_in_pounds: #<BigDecimal:7fc487ee9118,'0.1E1',9(18)>, width: nil, height: nil, thickness: nil>, #<BookVersion id: 1031, book_id: 2848, name: "lb", isbn: "12312333333", inventory: "02", price: #<BigDecimal:7fc487ee8f88,'0.2244E2',18(18)>, famis_price: nil, famis_number: "", weight_in_pounds: #<BigDecimal:7fc487ee8e98,'0.1E1',9(18)>, width: nil, height: nil, thickness: nil>, #<BookVersion id: 1032, book_id: 2848, name: "hc", isbn: "111213213131", inventory: nil, price: #<BigDecimal:7fc487ee8b50,'0.1212E4',9(18)>, famis_price: nil, famis_number: "", weight_in_pounds: #<BigDecimal:7fc487ee89c0,'0.1E1',9(18)>, width: nil, height: nil, thickness: nil>] 
    >> @book.update_attributes(params[:book]) 
    => false 

不過，這只是當我用更好的錯誤和update_attributes之前凍結控制器。在我更新屬性並嘗試運行之前，我實際上已將@book.book_versions置於控制器中，但它仍然不起作用。

Answer 1

所以我想出了一些hackery ...出於某種原因，你必須先將它們加載到內存中。爲了做到這一點，你必須在書籍版本上執行某種功能。只是撥打book.book_versions還不夠：

@book.book_versions.sort_by(&:name) # this line is to load the book_versions, without it book_versions will not update!! it's a bug in rails I discovered 
    if @book.update_attributes(params[:book]) #<-- returns false finally