Will map through all associations defined on a rails model and collect the result of a shared method

map_through_associations.rb

klas = item_type.constantize
has_many_associations = klas.reflections.collect { |_, c| c.class_name if c.macro == :has_many }.compact
has_one_associations = klas.reflections.collect { |_, c| c.class_name if c.macro == :has_one }.compact

instance = klas.find item_id

@result = instance.some_method

has_one_associations.each do |assoc_string|
  assoc_string = assoc_string.underscore
  if instance.respond_to? assoc_string
    assoc = instance.send(assoc_string)
    if assoc.respond_to?(:some_method) && !assoc.nil?
      @result += assoc.some_method
    end
  end
end

has_many_associations.each do |assoc_string|
  assoc_string = assoc_string.pluralize.underscore
  if instance.respond_to? assoc_string
    instance.send(assoc_string).each do |assoc|
      if assoc.respond_to?(:some_method) && !assoc.nil?
        @result += assoc.some_method
      end
    end
  end
end