I needed a way to get a list of the subclasses that inherit a specific.
Unfortunately there is no method like Class.subclasses
(there is Class.superclass, though) so I had to look for
another way to achieve this. Let’s say, we want to have an array
containing all subclasses as a class variable of our superclass
Strategy. In order to fill the array we’ll overwrite the
inherited class method of Class.
class Strategy
@subclasses = Array.new
class << self
def inherited(klass)
@subclasses << klass
end
def subclasses
@subclasses.join(', ')
end
end
end
Now, every time a class extends Strategy our new
inherited method is called and adds the class to our array.
class StrategyA < Strategy; end
class StrategyB < Strategy; end
class StrategyC < Strategy; end
# Let's get the current list of subclasses
puts Strategy.subclasses # will output StrategyA, StrategyB, StrategyC
What happens if a class inherits any of our subclasses? Well, as long as
you don’t overwrite the inherited method again it’s also
added to the array.