Ruby on Rails-从父类为每个子类调用一个方法

Question

I'm using Ruby on Rails with the following class structure:

class Parent
  def self.parse
    self.subclasses.each(&:parse) # how to fix this?
  end
end

class Child1 < Parent
  def self.parse
    # ...
  end
end

class Child2 < Parent
  def self.parse
    # ...
  end
end

I'd like to do something like:

Parent.parse
=> Child1.parse and Child2.parse

But actually the child classes are not loaded and so the subclasses methods give empty array.

Is there a easy way to do this very common task?

Answer 1

This happens because rails autoloads classes: Parent doesn't know about its subclasses until they used somewhere or required.

Just require them all manually from the Parent class:

# parent.rb
require 'child1'
require 'child2'

class Parent
  def self.parse
    self.subclasses.each(&:parse) # how to fix this?
  end
end