Module: ActiveModel::Validations::HelperMethods

Defined in:
lib/active_model/validations/unchanged_validator.rb

Instance Method Summary collapse

Instance Method Details

#validates_unchanged(*attr_names) ⇒ Object

Validates that the specified attributes are unchanged (unless the record is new). Happens by default on save.

class Person < ActiveRecord::Base
  validates_unchanged :first_name
end

The first_name attribute must be in the object and it must not have changed.

Configuration options:

  • :message - A custom error message (default is: “must not change”).

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



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# File 'lib/active_model/validations/unchanged_validator.rb', line 30

def validates_unchanged(*attr_names)
  validates_with UnchangedValidator, _merge_attributes(attr_names)
end