rails built in datetime validation

Question

Does rails do any validation for datetime? I found a plugin http://github.com/adzap/validates_timeliness/tree/master, but it seems like something that should come in out of the box.

Answer 1

There's no built-in ActiveRecord validator for DateTimes, but you can easily add this sort of capability to an ActiveRecord model, without using a plugin, with something like this:

class Thing < ActiveRecord::Base
  validate :happened_at_is_valid_datetime

  def happened_at_is_valid_datetime
    errors.add(:happened_at, 'must be a valid datetime') if ((DateTime.parse(happened_at) rescue ArgumentError) == ArgumentError)
  end
end

Answer 2

Gabe's answer didn't work for me, so here's what I did to validate my dates:

class MyModel < ActiveRecord::Base
  validate :mydate_is_date?

  private

  def mydate_is_date?
    if !mydate.is_a?(Date)
      errors.add(:mydate, 'must be a valid date') 
    end
  end
end

I was just looking to validate that the date is in fact a date, and not a string, character, int, float, etc...

More complex date validation can be found here: https://github.com/codegram/date_validator

Answer 3

Recent versions of Rails will type cast values before validation, so invalid values will be passed as nils to custom validators. I'm doing something like this:

# app/validators/date_time_validator.rb
class DateTimeValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    if record.public_send("#{attribute}_before_type_cast").present? && value.blank?
      record.errors.add(attribute, :invalid)
    end
  end
end

# app/models/something.rb
class Something < ActiveRecord::Base
  validates :sold_at, date_time: true
end

# spec/models/something_spec.rb (using factory_girl and RSpec)
describe Something do
  subject { build(:something) }

  it 'should validate that :sold_at is datetimey' do
    is_expected.not_to allow_value(0, '0', 'lorem').for(:sold_at).with_message(:invalid)
    is_expected.to allow_value(Time.current.iso8601).for(:sold_at)
  end
end

Answer 4

You can create a custom datetime validator by yourself

1) create a folder called validators in inside app directory

2) create a file datetime_validator.rb. with the following content inside app/validators directory

 class DatetimeValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    if ((DateTime.parse(value) rescue ArgumentError) == ArgumentError)  
      record.errors[attribute] << (options[:message] || "must be a valid datetime")
    end
  end
end

3) Apply this validation on model

class YourModel < ActiveRecord::Base
  validates :happend_at, datetime: true
end

4) Add the below line in application.rb

config.autoload_paths += %W["#{config.root}/app/validators/"]

5) Restart your rails application

Note: The above method tested in rails 4

Answer 5

I recommend a gem date_validator. See https://rubygems.org/gems/date_validator. It is well maintained and its API is simple and compact.