i have a question about how validates_presence_of works as it pertains to a login system. when you create a user for the first time you can require that both their password and confirmation password are present. but on subsequent updates to the that record you have to enter a confirmation password and that's really annoying.
i've been looking around and i've seen solutions that like something like tihs:
validates_presence_of :confirmation_password, :if=>'required'
where does that ":if" part come from? i mean, how did whoever suggest that know that they could do that? is that a Rails or a Ruby thing?
any insight into that mechanism would be much appreciated.
It's a Rails thing...
http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#M000813
Configuration options:
* message - A custom error message (default is: "can.t be blank") * on - Specifies when this validation is active (default is :save, other options :create, :update) * if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.
