Rails ActiveRecord finder that accepts an array of IDs and preserves the order in the results

active_record.rb

# config/initializers/active_record.rb

module ActiveRecord
  class Base
    # Find by array of IDs, preserving order of IDs
    # See http://stackoverflow.com/a/25248122/83743
    def self.find_with_relevance(array_of_ids)
      array_of_ids = Array(array_of_ids) unless array_of_ids.is_a?(Array)
      self.find(array_of_ids).index_by(&:id).slice(*array_of_ids).values
    end
  end
end

enumerable.rb

# config/initializers/enumerable.rb

# This is necessary in Rails <= 2.3
module Enumerable
  def index_by_with_ordered_hash
    inject(ActiveSupport::OrderedHash.new) do |accum, elem|
      accum[yield(elem)] = elem
      accum
    end
  end
  alias_method_chain :index_by, :ordered_hash
end