Module DataMapper::Validations::ValidatesWithMethod
In: lib/dm-validations/validators/method_validator.rb

Methods

Public Instance methods

Validate using method called on validated object. The method must to return either true, or a pair of [false, error message string], and is specified as a symbol passed with :method option.

This validator does support multiple fields being specified at a time, but we encourage you to use it with one property/method at a time.

Real world experience shows that method validation is often useful when attribute needs to be virtual and not a property name.

@example Usage

  require 'dm-validations'

 class Page
   include DataMapper::Resource

   property :zip_code, String

   validates_with_method :zip_code,
                         :method => :in_the_right_location?

   def in_the_right_location?
     if @zip_code == "94301"
       return true
     else
       return [false, "You're in the wrong zip code"]
     end
   end

   # A call to valid? will return false and
   # populate the object's errors with "You're in the
   # wrong zip code" unless zip_code == "94301"
 end

[Validate]