vendor/rails/activesupport/lib/active_support/core_ext/date/behavior.rb

   1 require 'date'
   2
   3 module ActiveSupport #:nodoc:
   4   module CoreExtensions #:nodoc:
   5     module Date #:nodoc:
   6       module Behavior
   7         # Enable more predictable duck-typing on Date-like classes. See
   8         # Object#acts_like?.
   9         def acts_like_date?
  10           true
  11         end
  12
  13         # Date memoizes some instance methods using metaprogramming to wrap
  14         # the methods with one that caches the result in an instance variable.
  15         #
  16         # If a Date is frozen but the memoized method hasn't been called, the
  17         # first call will result in a frozen object error since the memo
  18         # instance variable is uninitialized.
  19         #
  20         # Work around by eagerly memoizing before freezing.
  21         #
  22         # Ruby 1.9 uses a preinitialized instance variable so it's unaffected.
  23         # This hack is as close as we can get to feature detection:
  24         begin
  25           ::Date.today.freeze.jd
  26         rescue => frozen_object_error
  27           if frozen_object_error.message =~ /frozen/
  28             def freeze #:nodoc:
  29               self.class.private_instance_methods(false).each do |m|
  30                 if m.to_s =~ /\A__\d+__\Z/
  31                   instance_variable_set(:"@#{m}", [send(m)])
  32                 end
  33               end
  34
  35               super
  36             end
  37           end
  38         end
  39       end
  40     end
  41   end
  42 end