Determine given module is rails engine

Question

Hi I have two modules

Admin
Blog (Blog is a rails engine) where Admin is a module for namespacing admin features of app, but Blog is a module representing rails engine. Is there a better way to determine which among them is engine, like a function "is_engine?"

Admin.is_engine?

=> false

Blog.is_engine?

=> true

Definately I can have a try catch thing to determine this

def is_engine? module
  module::Engine
  true
rescue NameError
  false
end

here

is_engine? Admin

will return false

is_engine? Blog

will return true

Thanks

Here is the link Documentation for rails engine, it might be helpful to you. According to your purpose you will have to use methods provided for the same. — Sumit Munot, Apr 30 '13 at 08:02

giorgian · Accepted Answer · 2013-04-30T08:58:06.390

I'm not sure I understand what you are trying to do: a Rails Engine is a class (a subclass of Rails::Engine), not a module.

If you have an instance, you could use:

admin.kind_of?(Rails::Engine)

If you have a class, you can use:

Something.ancestors.include?(Rails::Engine)

If what you have is a module, then it cannot be a subclass of Rails::Engine, and it's not an engine.

EDIT

If you have a module or constant something and want to know if there's a constant with a certain name in its namespace, you can use:

something.constants.include?(:Engine)