Rails 3 - Validation for Time existence

问题:

I have a model with a Time attribute. I want to check that time can not be empty (better choice probably would be to check that input is time but i have no ideas how to deal with that). I tried this validation:

#  id              :integer         not null, primary key
#  school_class_id :integer
#  meeting_time    :time
class Meeting < ActiveRecord::Base                                                    
  validates :meeting_time,
              :presence => { :message => "can't be empty!" }                                                            
end

Then i tried to check this in spec and this fails (empty time is ok but it should not be). What do i do wrong?

Rspec:

#  id              :integer         not null, primary key
#  school_class_id :integer
#  meeting_time    :time

require 'spec_helper'

describe Meeting do
  before(:each) do
    @class = FactoryGirl.create( :school_class )
    @attr_meeting = {
      :meeting_theme => 'Text is here',
      :meeting_date => "#{Date.today}",
      :meeting_time => "#{Time.now}",
      :meeting_room => '1234'
    }
  end

  describe "Validations" do
    describe "Rejection" do
      it "should reject blank time" do
        wrong_attr = @attr_meeting.merge( :meeting_time => "  " )
        @class.meetings.build( wrong_attr ).should_not be_valid
      end
    end
  end
end

Error:

 Meeting Validations Rejection should reject blank time
     Failure/Error: @class.meetings.build( wrong_attr ).should_not be_valid
       expected valid? to return false, got true

回答1:

In your example, you assign " " to the meeting_time, not nil or "". But Time object somehow can be successfuly generated from non-empty, even blank string. Setting meeting_time to "" or nil should solve yout problem.

Maybe I don't fully understand something, but I think it's not very logical and predictable behaviour. Need to take a look into the sources.