[LRUG] Better idiom for this?

[Michael Pavling]

Hiya,

Ruby (well... Rails) question...

I frequently have a need to return a collection of model objects, which
exclude some amount of records (by ID)

I want the flexibility to be able to do the exclusion on either instances
of the model, or just ids (as strings or integers).

I have previously used a named scope, and currently (3.2) have started to
use a class-method, but it's looking a little clunky/smelly to me...

  class Foo < ActiveRecord::Base
    class << self
      def excluding(*objects)
        objects = objects.flatten.delete_if(&:blank?)
        object_ids = objects.map { |object| object.respond_to?(:to_i) ?
object.to_i : object.id }
        object_ids.any? ? where(['id NOT IN (?)', object_ids]) : scoped
      end
    end
  end

  # so I can now call:
  Foo.excluding(some_foo_object)
  Foo.excluding(some_foo_object, another_foo_object)
  Foo.excluding([1,2,3])
  Foo.excluding(params[:foo_ids_to_exclude])
  etc.

OOI does anyone have a better idiom for this approach?

M
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