（转）Ruby on Rails 的检验方法(Validation Helpers)
可以自定义validate(), 这个方法在每次保存数据时都会被调用. 如: def validate if name.blank? && email.blank? errors.add_to_base(“You must specify a name or an email address”) end end 同时也可以自定义 validate_on_create(), validate_on_update()方法. valid?()方法可以随时调用,用来测试数据是否能通过校验 返回的错误信息可用 error_messages_for(model)方法显示. 如:
validates_acceptance_of 指定checkbox应该选中. (如:(*)我同意条款) 用法:validates_acceptance_of attr… [ options... ] 参数:message text 默认:“must be accepted.” 
n :save, :create, or :update
实例: class Order < ActiveRecord::Base
validates_acceptance_of :terms, :message => ”Please accept the terms to proceed” end
validates_associated 查验指定的object. 用法:validates_associated name… [ options... ] 参数:message text 默认: is “is invalid.” n :save, :create, or :update
实例: class Order < ActiveRecord::Base
has_many :line_items belongs_to :user validates_associated :line_items, :message => ”are messed up” validates_associated :user end
validates_confirmation_of 数据重校 用法:validates_confirmation_of attr… [ options... ] 参数:message text 默认 “doesn’t match confirmation.” n :save, :create, or :update
实例: 对密码表:
#第二表名为xxxx_confirmation class User < ActiveRecord::Base validates_confirmation_of :password end
validates_each 使用block检验一个或一个以上参数. 用法:validates_each attr… [ options... ] { |model, attr, value| … } 参数:allow_nil boolean 设为true时跳过nil对象. n :save, :create, or :update
实例: class User < ActiveRecord::Base
validates_each :name, :email do |model, attr, value| if value =~ /groucho|harpo|chico/i model.errors.add(attr,”You can’t be serious, #{value}”) end end end
validates_exclusion_of 确定被检对象不包括指定数据 用法:validates_exclusion_of attr…, :in => enum [ options... ] #enum指一切可用include?()判断的范围. 参数:allow_nil 设为true将直接跳过nil对象. :in (or :within) enumerable :message text 默认为: “is not included in the list.” n :save, :create, or :update
实例: class User < ActiveRecord::Base
validates_exclusion_of :genre, :in => %w{ polka twostep foxtrot }, :message =>”no wild music allowed” validates_exclusion_of :age, :in => 13..19, :message =>”cannot be a teenager” end
validates_inclusion_of 确认对象包括在指定范围 用法:validates_inclusion_of attr…, :in => enum [ options... ] 参数:allow_nil 设为true直接跳过nil对象 :in (or :within) enumerable An enumerable object. :message text 默认:“is not included in the list.” n :save, :create, or :update
实例: class User < ActiveRecord::Base
validates_inclusion_of :gender, :in => %w{ male female }, :message =>”should be ‘male’ or ‘female’” validates_inclusion_of :age, :in => 0..130, :message =>”should be between 0 and 130″ end
validates_format_of 用正则检验对象 用法:validates_format_of attr…, :with => regexp [ options... ] 参数:message text 默认为: “is invalid.” n :save, :create, or :update :with 正则表达式 实例: class User < ActiveRecord::Base validates_format_of :length, :with => /^d+(in|cm)/ end
validates_length_of 检查对象长度 用法:validates_length_of attr…, [ options... ] 参数:in (or :within) range :is integer :minimum integer :maximum integer :message text 默认文字会根据参数变动,可使用%d 取代确定的最大,最小或指定数据. n :save, :create, or :update :too_long text 当使用了 :maximum后的 :message :too_short text ( :minimum ) :wrong_length ( :is)
实例: class User < ActiveRecord::Base
validates_length_of :name, :maximum => 50 validates_length_of :password, :in => 6..20 validates_length_of :address, :minimum => 10, :message =>”seems too short” end
validates_numericality_of 检验对象是否为数值 用法:validates_numericality_of attr… [ options... ] 参数:message text 默认 “is not a number.” n :save, :create, or :update nly_integer
实例: class User < ActiveRecord::Base
validates_numericality_of :height_in_meters validates_numericality_of :age, nly_integer => true end
validates_presence_of 检验对象是否为空 用法:validates_presence_of attr… [ options... ] 参数:message text 默认:“can’t be empty.” n :save, :create, or :update
实例: class User < ActiveRecord::Base
validates_presence_of :name, :address end
validates_uniqueness_of 检验对象是否不重复 用法:validates_uniqueness_of attr… [ options... ] 参数:message text 默认: “has already been taken.” n :save, :create, or :update :scope attr 指定范围
实例: class User < ActiveRecord::Base
validates_uniqueness_of :name end
class User < ActiveRecord::Base
validates_uniqueness_of :name, :scope =>”group_id” end #指定在同一group_id的条件下不重复.
E-Mail地址格式: validates_format_of :email, :with => /^([^@s]+)@((?:[-a-z0-9]+.)+[a-z]{2,})$/i, :message => ‘email must be valid’
网址格式: validates_uri_existence_of :url, :with => /(^$)|(^(http|https)://[a-z0-9] ([-.]{1}[a-z0-9] )*.[a-z]{2,5}(([0-9]{1,5})?/.*)?$)/ix
