method

validates_exclusion_of

v1.2.6 - Show latest stable - Class: ActiveRecord::Validations::ClassMethods

validates_exclusion_of(*attr_names)

public

Validates that the value of the specified attribute is not in a particular enumerable object.

  class Person < ActiveRecord::Base
    validates_exclusion_of :username, :in => %w( admin superuser ), :message => "You don't belong here"
    validates_exclusion_of :age, :in => 30..60, :message => "This site is only for under 30 and over 60"
  end

Configuration options:

in - An enumerable object of items that the value shouldn’t be part of
message - Specifies a customer error message (default is: "is reserved")
allow_nil - If set to true, skips this validation if the attribute is null (default is: false)
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.

# File activerecord/lib/active_record/validations.rb, line 629
      def validates_exclusion_of(*attr_names)
        configuration = { :message => ActiveRecord::Errors.default_error_messages[:exclusion], :on => :save }
        configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)

        enum = configuration[:in] || configuration[:within]

        raise(ArgumentError, "An object with the method include? is required must be supplied as the :in option of the configuration hash") unless enum.respond_to?("include?")

        validates_each(attr_names, configuration) do |record, attr_name, value|
          record.errors.add(attr_name, configuration[:message]) if enum.include?(value)
        end
      end

validates_exclusion_of

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