Rails + 单表继承：如何自定义验证错误消息？答案

【问题标题】：Rails + Single Table Inheritance: How to customize validation error message?Rails + 单表继承：如何自定义验证错误消息？
【发布时间】：2014-07-09 02:46:24
【问题描述】：

我有一个父类：

class Address < ActiveRecord::Base
  ...
  validates_presence_of :first_name
  validates_presence_of :last_name
  validates_presence_of :street_address
  validates_presence_of :street_address2
  validates_presence_of :zip_code
  validates_presence_of :city
  validates_presence_of :state_id
  validates_presence_of :phone_number

end

还有两个子类：

class ShippingAddress < Address
end


class BillingAddress < Address
end

但是，当我在表单上创建无效记录时（我同时创建两个），ShippingAddress 和 BillingAddress 的验证错误是相同的，这是我不想要的：

First name can't be blank
First name can't be blank
Last name can't be blank
Last name can't be blank
Street address can't be blank
Street address can't be blank
Street address2 can't be blank
Street address2 can't be blank
Zip code can't be blank
Zip code can't be blank
City can't be blank
City can't be blank
Phone number can't be blank
Phone number can't be blank

如何在验证错误前面加上 "Shipping address first name can't be blank" 这样的类名？

== 更新 ==

Yoshi 的回答在我尝试时不起作用：

class Address < ActiveRecord::Base  
  validates_presence_of :first_name, message: I18n.t("activerecord.errors.models.#{self.model_name.to_s.underscore}.attributes.first_name")




Nets-Mac-Pro:ilook emai$ be rails c
Loading development environment (Rails 4.1.1)
irb(main):001:0> s = ShippingAddress.new
=> #<ShippingAddress id: nil, first_name: nil, last_name: nil, street_address: nil, street_address2: nil, zip_code: nil, phone_number: nil, created_at: nil, updated_at: nil, state_id: nil, city: nil, type: "ShippingAddress", order_id: nil>
irb(main):002:0> s.valid?
=> false
irb(main):003:0> s.errors.full_messages
=> ["First name translation missing: en.activerecord.errors.models.address.attributes.first_name", "Last name can't be blank", "Street address can't be blank", "Street address2 can't be blank", "Zip code can't be blank", "City can't be blank", "State can't be blank", "Phone number can't be blank"]

它说型号名称是 Address 而不是 ShippingAddress。我猜这是急切的加载。

【问题讨论】：

标签： ruby-on-rails

【解决方案1】：

Rails 使用human_attribute_name 将属性名称转换为人类可读的形式。您可以尝试在 ShippingAddress 和 BillingAddress 中覆盖此类方法，以避免在您的语言环境文件中指定每个验证消息。

class ShippingAddress < Address
  def self.human_attribute_name(*args, &block)
    "Shipping address #{ super }"
  end
end

class BillingAddress < Address
  def self.human_attribute_name(*args, &block)
    "Billing address #{ super }"
  end
end

【讨论】：

【解决方案2】：

为了解决这个问题，我刚刚将它添加到我的 en.yml 文件中：

en:
  activerecord:
    attributes:
      shipping_address:
        first_name: "Shipping address first name"
        last_name: "Shipping address last name"
        street_address: "Shipping address street address"
        street_address2: "Shipping address apt/suite"
        zip_code: "Shipping address zip code"
        city: "Shipping address city"
        state_id: "Shipping address state"
        phone_number: "Shipping address phone number"
      billing_address:
        first_name: "Billing address first name"
        last_name: "Billing address last name"
        street_address: "Billing address street address"
        street_address2: "Billing address apt/suite"
        zip_code: "Billing address zip code"
        city: "Billing address city"
        state_id: "Billing address state"
        phone_number: "Billing address phone number"

【讨论】：