ruby-on-rails - ActiveRecord::AssociationTypeMismatch {} 是 Hash 的一个实例(#70364214688040)

Question

以下模型使用“class_name”:

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

在我的 Controller 中，我正在尝试构建一个新实例:

@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"}})

以下参数给了我错误

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)

为了绕过这个，我正在使用这个:

@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"}

然后，我尝试在模型中包含以下内容:

accepts_nested_attributes_for :origin
accepts_nested_attributes_for :destination

但是我得到了一个失败的空白验证。

如何修复模型以允许嵌套属性？

Answer 1

问题在于您试图将散列传递给作者方法以获取原点和位置，并且它需要一个实例位置。

长话短说，只需查看 accepts_nested_attributes_for

您看到的验证错误可能是一种未满足的验证。您可能需要检查货件和位置对象的错误消息，例如:@shipment.errors.messagesaccepts_nested_attributes_for将添加 origin_attributes=和 destination_attributes=作家方法，这将使事情发挥作用。您必须更改传递给 new 的哈希键来自 origin至 origin_attributes , 和 destination至 destination_attributes .

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

  accepts_nested_attributes_for :origin, :destination
end

然后你可以使用:

@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"
  }
})

作为一个完全不相关的旁注，我将这些属性称为 source_location和 destination_location或类似。属性名称上的“位置”清楚地表明您在谈论位置，而不是其他事物。