Question

我正在努力验证postal_code并使用不同的正则表达式，具体取决于country_code属性。我尝试了以下方法，但它不起作用：

class Venue < ActiveRecord::Base
  ...
  attr_accessible :postal_code
  attr_accessible :country_code
  ...
  validates_presence_of     :country_code
  validates_length_of       :country_code,  :maximum => 2,    :allow_nil => true
  validates_inclusion_of    :country_code,  :in => %w( US CA AU GB )
  validates_presence_of     :postal_code
  validates_length_of       :postal_code,   :maximum => 10,   :allow_nil => true

  validates_format_of       :postal_code,   :with => %r{^\d{4}$},
                                            :message => "should be in the format 1111",
                                            :allow_nil => true,
                                            :if => :country_code == 'AU'
  validates_format_of       :postal_code,   :with => %r{^\d{5}([\-]\d{4})?$},
                                            :message => "should be in the format 11111 or 11111-1111",
                                            :allow_nil => true,
                                            :if => :country_code == 'US'
  validates_format_of       :postal_code,   :with =>%r{^[ABCEGHJKLMNPRSTVXY]{1}\d{1}[A-Z]{1} *\d{1}[A-Z]{1}\d{1}$},
                                            :message => "should be in the format A1A 1A1 (try making letters capitalized)",
                                            :allow_nil => true,
                                            :if => :country_code == 'CA'

  # ridculously long (but thorough) regex courtesy of Wikipedia (http://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom)
  validates_format_of       :postal_code,   :with => %r{^(GIR 0AA)|(((A[BL]|B[ABDHLNRSTX]?|C[ABFHMORTVW]|D[ADEGHLNTY]|E[HNX]?|F[KY]|G[LUY]?|H[ADGPRSUX]|I[GMPV]|JE|K[ATWY]|L[ADELNSU]?|M[EKL]?|N[EGNPRW]?|O[LX]|P[AEHLOR]|R[GHM]|S[AEGKLMNOPRSTY]?|T[ADFNQRSW]|UB|W[ADFNRSV]|YO|ZE)[1-9]?[0-9]|((E|N|NW|SE|SW|W)1|EC[1-4]|WC[12])[A-HJKMNPR-Y]|(SW|W)([2-9]|[1-9][0-9])|EC[1-9][0-9]) [0-9][ABD-HJLNP-UW-Z]{2})$},
                                            :message => "invalid postal code (try making letters capitalized)",
                                            :allow_nil => true,
                                            :if => :country_code == 'GB'

我是完全不在此预订上，还是仅仅是:if选项的格式？

Answer 1

作为参考，:if =>参数接受方法而不是条件，例如你可以

validate_presence_of :foo, :if => :country_is_gb?

def country_is_gb?
  country_code == 'GB'
end

但如上所述，冗长或复杂的验证最好在单独的自定义验证器中完成。

Answer 2

看一下这个截屏视频http://asciicasts.com/episodes/211-validations-in-rails-3 我认为它只是为您的邮政编码编写自定义验证函数的时间。

模型的条件验证依赖于模型属性的值

2 个答案: