--- /dev/null
+class Object
+ # An object is blank if it's false, empty, or a whitespace string.
+ # For example, "", " ", +nil+, [], and {} are blank.
+ #
+ # This simplifies
+ #
+ # if !address.nil? && !address.empty?
+ #
+ # to
+ #
+ # if !address.blank?
+ def blank?
+ respond_to?(:empty?) ? empty? : !self
+ end
+
+ # An object is present if it's not blank.
+ def present?
+ !blank?
+ end
+end
+
+class NilClass #:nodoc:
+ def blank?
+ true
+ end
+end
+
+class FalseClass #:nodoc:
+ def blank?
+ true
+ end
+end
+
+class TrueClass #:nodoc:
+ def blank?
+ false
+ end
+end
+
+class Array #:nodoc:
+ alias_method :blank?, :empty?
+end
+
+class Hash #:nodoc:
+ alias_method :blank?, :empty?
+end
+
+class String #:nodoc:
+ def blank?
+ self !~ /\S/
+ end
+end
+
+class Numeric #:nodoc:
+ def blank?
+ false
+ end
+end