Rails ActiveRecord 2.3.15 hash that supports procs as values (can be used with ActiveRecord default_scope)

proxy_hash.rb

module Proxies
  # ProxyHash can be used when there is a need to have procs inside hashes, as it executes all procs before returning the hash
  # ==== Example
  #   Proxies::ProxyHash.new(:company_id => lambda{logged_user.try(:company_id)})
  class ProxyHash < ::Hash
    instance_methods.each{|m| undef_method m unless m =~ /(^__|^nil\?$|^method_missing$|^object_id$|proxy_|^respond_to\?$|^send$)/}

    def [](_key)
      call_hash_procs(@target, @original_hash)
      ProxyHash.new(@original_hash[_key])
    end

    # Returns the \target of the proxy, same as +target+.
    def proxy_target
      @target
    end

    # Does the proxy or its \target respond to +symbol+?
    def respond_to?(*args)
      super(*args) || @target.respond_to?(*args)
    end

    # Returns the target of this proxy, same as +proxy_target+.
    def target
      @target
    end

    # Sets the target of this proxy to <tt>\target</tt>.
    def target=(target)
      @target = target
    end

    def send(method, *args)
      if respond_to?(method)
        super
      else
        @target.send(method, *args)
      end
    end

    def initialize(*_find_args)
      @original_hash = _find_args.extract_options!

      @target = @original_hash.deep_dup
    end

    private
      # Forwards any missing method call to the \target.
      def method_missing(method, *args, &block)
        if @target.respond_to?(method)
          call_hash_procs(@target, @original_hash)
          @target.send(method, *args, &block)
        else
          super
        end
      end

      def call_hash_procs(_hash, _original_hash)
        _hash.each do |_key, _value|
          if _value.is_a?(Hash)
            call_hash_procs(_value, _original_hash[_key]) if _original_hash.has_key?(_key)
          else
            _hash[_key] = _original_hash[_key].call if _original_hash[_key].is_a?(Proc)
          end
        end
      end
  end
end