ActiveModel AttributeMethods ClassMethods module ClassMethods Ruby on Rails 5.2.8.1 Since v3.0.20 Available in: 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: … v3.0.20 v3.1.12 v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2 No documentation comment. Methods (defined here) # alias_attribute # attribute_alias # attribute_alias? # attribute_method_affix # attribute_method_prefix # attribute_method_suffix # define_attribute_method # define_attribute_methods # undefine_attribute_methods Private methods (5) Implementation detail — not part of the public API. # attribute_method_matchers_cache # attribute_method_matchers_matching # define_proxy_call # generated_attribute_methods # instance_method_already_implemented?