vendor/rails/activesupport/lib/active_support/core_ext/blank.rb

   1 class Object
   2   # An object is blank if it's false, empty, or a whitespace string.
   3   # For example, "", "   ", +nil+, [], and {} are blank.
   4   #
   5   # This simplifies
   6   #
   7   #   if !address.nil? && !address.empty?
   8   #
   9   # to
  10   #
  11   #   if !address.blank?
  12   def blank?
  13     respond_to?(:empty?) ? empty? : !self
  14   end
  15
  16   # An object is present if it's not blank.
  17   def present?
  18     !blank?
  19   end
  20 end
  21
  22 class NilClass #:nodoc:
  23   def blank?
  24     true
  25   end
  26 end
  27
  28 class FalseClass #:nodoc:
  29   def blank?
  30     true
  31   end
  32 end
  33
  34 class TrueClass #:nodoc:
  35   def blank?
  36     false
  37   end
  38 end
  39
  40 class Array #:nodoc:
  41   alias_method :blank?, :empty?
  42 end
  43
  44 class Hash #:nodoc:
  45   alias_method :blank?, :empty?
  46 end
  47
  48 class String #:nodoc:
  49   def blank?
  50     self !~ /\S/
  51   end
  52 end
  53
  54 class Numeric #:nodoc:
  55   def blank?
  56     false
  57   end
  58 end