Rails validation regex not working: invalid though input correct -

i trying validate kind of datetime field regex. regex correct - tested on rubular - rails throws error on field: invalid.

in model have:

validates :ddate, presence: true, format: { with: /\a(\d\d\.){2}\d{4} \d\d:\d\d\z/ } 

in form enter: 25.12.2015 20:15 , validation error: ddate invalid

i tried break down , started with:

validates :ddate, presence: true, format: { with: /\a\d\d/ } 

which worked expected, tried:

validates :ddate, presence: true, format: { with: /\a\d\d\./ } 

which did not work anymore.

any hints, why not working?

i using rails 4.2.4 , ruby 2.2.1p85.

you passing string, make instead:

attr_accessor :ddate_string  validates :ddate_string, presence: true, format: { with: /\d{1,2}\.\d{1,2}\.\d{4} \d{1,2}:\d{1,2}/ }  before_save :set_ddate  def set_ddate   self.ddate = ddate_string end 

you can run regex validations against strings.