驗證是否存在一個或另一個字段（XOR）

Question

如何驗證一個字段或另一個字段的存在，但不是兩個字段或至少一個字段？

Answer 1

如果條件語句添加到numericality驗證，像這樣你的代碼將工作：

class Transaction < ActiveRecord::Base 
    validates_presence_of :date 
    validates_presence_of :name 

    validates_numericality_of :charge, allow_nil: true 
    validates_numericality_of :payment, allow_nil: true 


    validate :charge_xor_payment 

    private 

    def charge_xor_payment 
     unless charge.blank?^payment.blank? 
     errors.add(:base, "Specify a charge or a payment, not both") 
     end 
    end 

end 

Answer 2

鋼軌3.

class Transaction < ActiveRecord::Base 
    validates_presence_of :date 
    validates_presence_of :name 

    validates_numericality_of :charge, :unless => proc{|obj| obj.charge.blank?} 
    validates_numericality_of :payment, :unless => proc{|obj| obj.payment.blank?} 


    validate :charge_xor_payment 

    private 

    def charge_xor_payment 
     if !(charge.blank?^payment.blank?) 
     errors[:base] << "Specify a charge or a payment, not both" 
     end 
    end 
end 

Answer 3

validate :father_or_mother 

#Father姓或母姓例強制

def father_or_mother 
     if father_last_name == "Last Name" or father_last_name.blank? 
      errors.add(:father_last_name, "cant blank") 
      errors.add(:mother_last_name, "cant blank") 
     end 
end 

試試上面的簡單例子。

Answer 4

class Transaction < ActiveRecord::Base 
    validates_presence_of :date 
    validates_presence_of :name 

    validates_numericality_of :charge, allow_nil: true 
    validates_numericality_of :payment, allow_nil: true 


    validate :charge_xor_payment 

    private 

    def charge_xor_payment 
     if [charge, payment].compact.count != 1 
     errors.add(:base, "Specify a charge or a payment, not both") 
     end 
    end 

end 

，你甚至可以用3個或多個值做到這一點：

if [month_day, week_day, hour].compact.count != 1 

Answer 5

我認爲這是Rails的更地道3+：

如：用於驗證的user_name或email一個是目前：

validates :user_name, presence: true, unless: ->(user){user.email.present?} 
validates :email, presence: true, unless: ->(user){user.user_name.present?} 

Answer 6

我把我的答案在下面這個問題。在這個例子中:description和:keywords是字段，其中這一個不能爲空：

validate :some_was_present 

    belongs_to :seo_customable, polymorphic: true 

    def some_was_present 
    desc = description.blank? 
    errors.add(desc ? :description : :keywords, t('errors.messages.blank')) if desc && keywords.blank? 
    end