As Roman says, it can be done with
ActiveSupport::Deprecation.deprecate_methods(target_module, *deprecated_methods)
where:
target_module
is the module or class where the method belongs.
deprecated_methods
is an array of symbols.
In the last methods can be given options to customize the deprecation message.
ActiveSupport::Deprecation.deprecate_methods(target_module, :old_method, \
:other_old_method => :new_method, :another_old_method => "custom message")
This example shows the default message when old_method is called, give a comment to "use new_method instead", in the second one, and the custom message with :another_old_method.
Notes: The deprecated methods should be defined (before) and will be executed. The :new_method is not called automatically. (there are more options, but I don't know them)