instance method `instance_method_already_implemented?`

Ruby on Rails 6.1.7.10

Since v2.2.3

Available in: v2.2.3 v2.3.18 v3.0.20 v3.1.12 v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

instance_method_already_implemented?(method_name)

Raises an ActiveRecord::DangerousAttributeError exception when an Active Record method is defined in the model, otherwise false.

class Person < ActiveRecord::Base
  def save
    'already defined by Active Record'
  end
end

Person.instance_method_already_implemented?(:save)
# => ActiveRecord::DangerousAttributeError: save is defined by Active Record. Check to make sure that you don't have an attribute or method with the same name.

Person.instance_method_already_implemented?(:name)
# => false

Parameters

method_name req

Source

# File activerecord/lib/active_record/attribute_methods.rb, line 91
      def instance_method_already_implemented?(method_name)
        if dangerous_attribute_method?(method_name)
          raise DangerousAttributeError, "#{method_name} is defined by Active Record. Check to make sure that you don't have an attribute or method with the same name."
        end

        if superclass == Base
          super
        else
          # If ThisClass < ... < SomeSuperClass < ... < Base and SomeSuperClass
          # defines its own attribute method, then we don't want to overwrite that.
          defined = method_defined_within?(method_name, superclass, Base) &&
            ! superclass.instance_method(method_name).owner.is_a?(GeneratedAttributeMethods)
          defined || super
        end
      end

Defined in activerecord/lib/active_record/attribute_methods.rb line 91 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::AttributeMethods::ClassMethods

Signature

Parameters