Method: ActiveModel::Validations::HelperMethods#validates_comparison_of

Defined in:
activemodel/lib/active_model/validations/comparison.rb

#validates_comparison_of(*attr_names) ⇒ Object

Validates the value of a specified attribute fulfills all defined comparisons with another value, proc, or attribute.

class Person < ActiveRecord::Base
  validates_comparison_of :value, greater_than: 'the sum of its parts'
end

Configuration options:

  • :message - A custom error message (default is: “failed comparison”).

  • :greater_than - Specifies the value must be greater than the supplied value. The default error message for this option is _“must be greater than %count”_.

  • :greater_than_or_equal_to - Specifies the value must be greater than or equal to the supplied value. The default error message for this option is _“must be greater than or equal to %count”_.

  • :equal_to - Specifies the value must be equal to the supplied value. The default error message for this option is _“must be equal to %count”_.

  • :less_than - Specifies the value must be less than the supplied value. The default error message for this option is _“must be less than %count”_.

  • :less_than_or_equal_to - Specifies the value must be less than or equal to the supplied value. The default error message for this option is _“must be less than or equal to %count”_.

  • :other_than - Specifies the value must not be equal to the supplied value. The default error message for this option is _“must be other than %count”_.

There is also a list of default options supported by every validator: :if, :unless, :on, :allow_nil, :allow_blank, and :strict . See ActiveModel::Validations::ClassMethods#validates for more information.

The validator requires at least one of the following checks to be supplied. Each will accept a proc, value, or a symbol which corresponds to a method:

  • :greater_than

  • :greater_than_or_equal_to

  • :equal_to

  • :less_than

  • :less_than_or_equal_to

  • :other_than

For example:

class Person < ActiveRecord::Base
  validates_comparison_of :birth_date, less_than_or_equal_to: -> { Date.today }
  validates_comparison_of :preferred_name, other_than: :given_name, allow_nil: true
end



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# File 'activemodel/lib/active_model/validations/comparison.rb', line 85

def validates_comparison_of(*attr_names)
  validates_with ComparisonValidator, _merge_attributes(attr_names)
end