rails 3 validation of a string

Question

hiho

Is there any way to tell rails that my string may not be \'something\'?

I am searching for something like

validates :string, :not =>          


        

Answer 1

A couple of ways. If you have exact list of what it can't be:

validates_exclusion_of :string, :in => ["something", "something else"]

If you want to ensure that it doesn't exist as a substring at all:

validates_format_of :string, :with => /\A(?!something)\Z/

If it is more complicated and you want to hide the messy details:

validate :not_something

def not_something
  errors.add(:string, "Can't be something") if string =~ /something/
end