diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/class/subclasses.rb')
-rw-r--r-- | activesupport/lib/active_support/core_ext/class/subclasses.rb | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/class/subclasses.rb b/activesupport/lib/active_support/core_ext/class/subclasses.rb new file mode 100644 index 0000000000..c166ce8079 --- /dev/null +++ b/activesupport/lib/active_support/core_ext/class/subclasses.rb @@ -0,0 +1,58 @@ +require 'active_support/core_ext/object/blank' + +class Class #:nodoc: + # Returns an array with the names of the subclasses of +self+ as strings. + # + # Integer.subclasses # => ["Bignum", "Fixnum"] + def subclasses + Class.subclasses_of(self).map { |o| o.to_s } + end + + def reachable? #:nodoc: + eval("defined?(::#{self}) && ::#{self}.equal?(self)") + end + + # Rubinius + if defined?(Class.__subclasses__) + def descendents + subclasses = [] + __subclasses__.each {|k| subclasses << k; subclasses.concat k.descendents } + subclasses + end + else + # MRI + begin + ObjectSpace.each_object(Class.new) {} + + def descendents + subclasses = [] + ObjectSpace.each_object(class << self; self; end) do |k| + subclasses << k unless k == self + end + subclasses + end + # JRuby + rescue StandardError + def descendents + subclasses = [] + ObjectSpace.each_object(Class) do |k| + subclasses << k if k < self + end + subclasses.uniq! + subclasses + end + end + end + + # Exclude this class unless it's a subclass of our supers and is defined. + # We check defined? in case we find a removed class that has yet to be + # garbage collected. This also fails for anonymous classes -- please + # submit a patch if you have a workaround. + def self.subclasses_of(*superclasses) #:nodoc: + subclasses = [] + superclasses.each do |klass| + subclasses.concat klass.descendents.select {|k| k.name.blank? || k.reachable?} + end + subclasses + end +end |