的ActiveRecord :: AssociationTypeMismatch {}這是哈希（＃70364214688040）的一個實例，使用 「CLASS_NAME」

Question

以下模型：

class Shipment < ApplicationRecord 
    belongs_to :origin,  :class_name => "Location" 
    belongs_to :destination,:class_name => "Location" 
end 

在我的控制，我試圖建立一個新的實例：

@shipment = Shipment.new({ 
"origin" => {"name"=>"12312", "country"=>"US", "city"=>"Cambridge", "state"=>"MA", "postal_code"=>"02138", "address1"=>"Massachusetts Avenue, 1234", "address2"=>"123213"}, 
"destination" => {"name"=>"12312", "country"=>"US", "city"=>"Cambridge", "state"=>"MA", "postal_code"=>"02138", "address1"=>"Massachusetts Avenue, 1234", "address2"=>"123213"}}) 

以下PARAMS給我的錯誤

ActiveRecord::AssociationTypeMismatch: Location(#70364217448000) expected, got {"name"=>"12312", "country"=>"US", "city"=>"Cambridge", "state"=>"MA", "postal_code"=>"02138", "address1"=>"Massachusetts Avenue, 1234", "address2"=>"123213"} which is an instance of Hash(#70364214688040) 

繞過這個，我用這：

@shipment = Shipment.new 
@shipment.build_origin  {"name"=>"12312", "country"=>"US", "city"=>"Cambridge", "state"=>"MA", "postal_code"=>"02138", "address1"=>"Massachusetts Avenue, 1234", "address2"=>"123213"} 
@shipment.build_destination {"name"=>"12312", "country"=>"US", "city"=>"Cambridge", "state"=>"MA", "postal_code"=>"02138", "address1"=>"Massachusetts Avenue, 1234", "address2"=>"123213"} 

於是，我試着在模型中包括以下內容：

accepts_nested_attributes_for :origin 
accepts_nested_attributes_for :destination 

但比我得到的失敗空白驗證。

如何修復模型以允許嵌套屬性？

Answer 1

存在的問題是，您嘗試將散列傳遞給原作者和位置的作者方法，並且期望實例位置。

長話短說，只是檢查出accepts_nested_attributes_for

您所看到的驗證錯誤可能是一個沒有被滿足一個驗證。您可能要檢查貨物和定位對象的錯誤信息，例：@shipment.errors.messages

accepts_nested_attributes_for將增加origin_attributes=和destination_attributes=作家方法，這將使事情的工作。您必須將您傳遞至new的散列鍵從origin更改爲origin_attributes，並將destination更改爲destination_attributes。

class Shipment < ApplicationRecord 
    belongs_to :origin, class_name: 'Location' 
    belongs_to :destination, class_name: 'Location' 

    accepts_nested_attributes_for :origin, :destination 
end 

然後你可以使用：

@shipment = Shipment.new({ 
    "origin_attributes" => { 
    "name" => "12312", "country" => "US", "city" => "Cambridge", "state" => "MA", "postal_code" => "02138", "address1" => "Massachusetts Avenue, 1234", "address2" => "123213" 
    }, 
    "destination_attributes" => { 
    "name" => "12312", "country" => "US", "city" => "Cambridge", "state" => "MA", "postal_code" => "02138", "address1" => "Massachusetts Avenue, 1234", "address2" => "123213" 
    } 
}) 

作爲一個完全無關的方面說明，我所說的這些屬性source_location和destination_location或相似。擁有屬性名稱的「位置」清楚地表明您正在談論地點，而不是其他事情。