Deprecate entire model in Rails

Question

I'm in the process of rewriting/refactoring a legacy application for a client from Rails 2.x to 3.x. As part of the refactoring I also want to step away from models/methods in our local language to a pure English code base.

This involves writing new methods for almost every feature. I solve this for methods by doing:

def english_method
  # ...
end

def native_method
  warn 'DEPRECATED, please use #english_method'
  english_method
end

This works fine for methods, and helps me track places where the old method is still being used, without breaking any code.

For classes (models) however, I've been doing:

class NativeClass < EnglishClass
  # DEPRECATED, Please use EnglishClass
end

class EnglishClass
  # ...
end

This "works", whenever NativeClass is called, the application keeps working, but I don't get any message in the log notifying me of a part of the application still calling NativeClass.

How can I make sure every "touch" of NativeClass actually results in a log error being written?

I tried (for no reason other than thinking "maybe this works") to do:

class NativeClass < EnglishClass
  -> { ActiveSupport::Deprecation.warn 'Native model is deprecated in favor of English' }
end

But that (obviously?) didn't work. I figure the lambda would be lazy loaded every time NativeClass is called, but my understanding of lambdas is still somewhat shallow, so I might be mistaken here.

Any clues on how to deprecate entire classes and send a warning message to my log when it's being touched?

Other "best practices" and or solutions for deprecation are welcome, but I'm not sure if it's a valid question for SO (and I don't want to risk this topic getting closed for this question).

Answer 1

Try to use like:

class NativeClass < EnglishClass
  def initialize
    ActiveSupport::Deprecation.warn "NativeClass is deprecated and may be removed from future releases, use EnglishClass instead.", caller
    super
  end
end

Answer 2

You might be better off just deprecating each method individually. This can easily be accomplished by using Rails' deprecate method and passing it a list of methods you want to deprecate. The list of methods defined within a class is available by passing false to public_instance_methods

class NativeClass < EnglishClass
  def method1
  end

  def method2
  end

  deprecate *public_instance_methods(false)
end

Note that it needs to be declared AFTER the last public method.