Validation Helpers（数据验证）

validates_acceptance_of

# checkbox 提交后的设置的默认值 

 

class Person < ActiveRecord::Base

  validates_acceptance_of :terms_of_service, :accept => 'yes'

end

 

validates_associated

# 关联验证

# 验证当前的model时，也要验证相关联的model

 

class Library < ActiveRecord::Base

  has_many :books

  validates_associated :books

end

 

# 不要对进行双向关联验证，这样会进行死循环的(infinite loop.)

 

validates_confirmation_of

# 重复性验证

# 用于验证密码，邮件

# 重复验证的元素必须以"_confirmation"结尾

 

class Person < ActiveRecord::Base

  validates_confirmation_of :email

end

 

<%= text_field :person, :email %>

<%= text_field :person, :email_confirmation %>

 

# 修改后，重复验证的元素不能为空

class Person < ActiveRecord::Base

  validates_confirmation_of :email

  validates_presence_of :email_confirmation

end

 

validates_exclusion_of

# 验证的属性是否不包含在给定集中

 

class Account < ActiveRecord::Base

  validates_exclusion_of :subdomain, :in => %w(www),

    :message => "Subdomain %{value} is reserved."

end

 

:in 用来预设的验证集合

 

validates_format_of

# 验证格式

 

class Product < ActiveRecord::Base

  validates_format_of :legacy_code, :with => /\A[a-zA-Z]+\z/,

    :message => "Only letters allowed"

end

 

:with 有来设置格式

 

validates_inclusion_of

# 验证的属性是否包含在给定集中

 

class Coffee < ActiveRecord::Base

  validates_inclusion_of :size, :in => %w(small medium large),

    :message => "%{value} is not a valid size"

end

 

:in 用来预设的验证集合

 

validates_length_of

# 验证的属性长度

 

class Person < ActiveRecord::Base

  validates_length_of :name, :minimum => 2

  validates_length_of :bio, :maximum => 500

  validates_length_of :password, :in => 6..20

  validates_length_of :registration_number, :is => 6

end

 

:minimum   # 设置属性最小长度

:maximum   # 设置属性最大长度

:in        # 指定一个区间

:is        # 必须指定一个值 

 

:wrong_length  # 长度发生错误时，显示的信息

:too_long      # 长度超出时，显示的信息

:too_short     # 长度不足时，显示的信息

 

validates_numericality_of

# 指定数字验证

 

class Player < ActiveRecord::Base

  validates_numericality_of :points

  validates_numericality_of :games_played, :only_integer => true

end

 

:only_integer       # 必须为整数

:greater_than       # >

:greater_than_or_equal_to   # >=

:equal_to           # =

:less_than          # <

:less_than_or_equal_to      # <=

:odd                # 奇数

:even               # 偶数

 

validates_presence_of

# 判空操作

 

class Person < ActiveRecord::Base

  validates_presence_of :name, :login, :email

end

 

validates_uniqueness_of

# 唯一性验证

 

class Account < ActiveRecord::Base

  validates_uniqueness_of :email

end

 

validates_with

# 使用验证类来进行验证

 

class Person < ActiveRecord::Base

  validates_with GoodnessValidator

end

 

class GoodnessValidator < ActiveRecord::Validator

  def validate

    if record.first_name == "Evil"

      record.errors[:base] << "This person is evil"

    end

  end

end

 

当发生错误信息时，没有缺省的错误信息，需要向error添加错误信息

 

validator类有两个缺省的参数

record    # 被验证的类

options   # 额外的选项

 

validates_each

# 使用block对多个值进行验证

 

 

Ref:

http://guides.rubyonrails.org/active_record_validations_callbacks.html