validates_timeliness

安装后

$ rails generate validates_timeliness:install

会生成 initializer 和 locale 配置文件！

使用例子：

validates_datetime :occurred_at

validates_date :date_of_birth, :before => lambda { 18.years.ago },
                              :before_message => "must be at least 18 years old"

validates_datetime :finish_time, :after => :start_time # Method symbol

validates_date :booked_at, :on => :create, :on_or_after => :today # See Restriction Shorthand.
validates_time :booked_at, :between => ['9.00am', '5:00pm']

validates_time :breakfast_time, :on_or_after => '6:00am',
                                :on_or_after_message => 'must be after opening time',
                                :before => :lunchtime,
                                :before_message => 'must be before lunch time'

如何使用？

class Person < ActiveRecord::Base
  validates_date :date_of_birth, :on_or_before => lambda { Date.current }
  # or
  validates :date_of_birth, :timeliness => {:on_or_before => lambda { Date.current }, :type => :date}
end

# or even on a specific record, per ActiveModel API.

@person.validates_date :date_of_birth, :on_or_before => lambda { Date.current }

其实和平常的‘校验’也没什么两样，只是我们对 日期／时间的校验 不常用罢了。如下：

validates_date     - validate value as date
validates_time     - validate value as time only i.e. '12:20pm'
validates_datetime - validate value as a full date and time
validates          - use the :timeliness key and set the type in the hash.

对于上面的 validates 方法，我们可以有如下选项：

:is_at        - Attribute must be equal to value to be valid
:before       - Attribute must be before this value to be valid
:on_or_before - Attribute must be equal to or before this value to be valid
:after        - Attribute must be after this value to be valid
:on_or_after  - Attribute must be equal to or after this value to be valid
:between      - Attribute must be between the values to be valid. Range or Array of 2 values.

:allow_nil    - Allow a nil value to be valid
:allow_blank  - Allows a nil or empty string value to be valid
:if           - Execute validation when :if evaluates true
:unless       - Execute validation when :unless evaluates false
:on           - Specify validation context e.g :save, :create or :update. Default is :save.

:ignore_usec  - Ignores microsecond value on datetime restrictions
:format       - Limit validation to a single format for special cases. Requires plugin parser.

还有一些配置工作Configuration， 在此就不多说了。