Question

I have a several classes that inherit from a single class:

class Bravo << Alpha
class Charlie << Alpha

Alpha has some class level variables:

class Alpha 
  @@terms 

  def initialize 
    ...
    @@terms ||= load_terms 
  end 
end 

OK, all is fine so far. But I’d like to access the class level variables from the console for troubleshooting purposes. Is this possible? I’ve tried:

# inst is an instance of Bravo for example
inst.class.superclass:terms
inst.@@terms
inst.class.superclass[:terms]

Didn’t expect any of that to really work, just grabbing at straws since I couldn’t find any answer to the question. I’ve confirmed that the class variables are there via:

>> inst.class.superclass.class_variables
=> [:terms]

OK, I can see that they are there, but is there any way to directly access them via the rails console?

Answer 1

You almost made it 🙂

class Alpha
  @@terms = 'foo'
end

class Bravo < Alpha
end

b = Bravo.new
puts b.class.class_variable_get '@@terms'
# => foo

It may look complicated, and it probably is so for a reason: to discourage people from messing with class’ internals (I don’t know if it’s true, I just made it up).

If you need this on a regular basis, add an accessor for it!

class Alpha
  @@terms = 'foo'

  def self.terms
    @@terms
  end
end


puts Alpha.terms
# => foo