Question

假设我有一个方法，它结合了几个地址字段，如下所示：

def address
    "#{street_address}, #{city}, #{state}, #{postal_code}, #{country}"
end

如何扩展方法以允许检查是否有任何字段已更改？基本上，我希望能够做到以下几点：

after_validation :geocode, :if => :address.changed?

我的模型如下：

class Place < ActiveRecord::Base

  attr_accessible :street_address, :city, :state, :postal_code, :country, :latitude, :longitude, :geocode_type
  geocoded_by :address

  after_validation :geocode#, :if => :address.changed?

  def address
    "#{street_address}, #{city}, #{state}, #{postal_code}, #{country}"
  end
end

还是有更好的方法可以一起做到这一点吗？

Answer 1

def address_changed?
  attrs = %w(street_address city state postal_code country)
  attrs.any?{|a| send "#{a}_changed?"}
end

Answer 2

有点笨重......

def address_changed?
  street_address_changed? || city_changed? || state_changed? || postal_code_changed? || country_changed?
end

如何创建使用“_changed？”的方法在合并的领域

2 个答案: