Validate Dates in Your Models 3

Posted by Bob Silva Fri, 08 Sep 2006 06:11:00 GMT

mojombo in #caboose, just released his first version of Chronic, a new Ruby Gem for natural language processing of Dates and Times. 
gem install chronic

irb:>
Chronic.parse('tomorrow')
    #=> Mon Aug 28 12:00:00 PDT 2006

Chronic.parse('monday', :context => :past)
    #=> Mon Aug 21 12:00:00 PDT 2006

Chronic.parse('this tuesday 5:00')
    #=> Tue Aug 29 17:00:00 PDT 2006

Chronic.parse('this tuesday 5:00', :ambiguous_time_range => :none)
    #=> Tue Aug 29 05:00:00 PDT 2006

Chronic.parse('may 27th', :now => Time.local(2000, 1, 1))
    #=> Sat May 27 12:00:00 PDT 2000

Chronic.parse('may 27th', :guess => false)
    #=> Sun May 27 00:00:00 PDT 2007..Mon May 28 00:00:00 PDT 2007
The thing I find really nice is that if you pass it a malformed date, it returns nil. This means, in your model validations, you can add: 
require 'chronic'

class Meeting < ActiveRecord::Base

  def validation
    errors.add :meeting_date, 'is not a valid date' if Chronic.parse(meeting_date.to_s).nil?
  end

end