Module: ActiveSupport::DescendantsTracker

Relationships & Source Files
Namespace Children
Modules: `ReloadedClassesFiltering`
Classes: `WeakSet`
Extension / Inclusion / Inheritance Descendants
Extended In: `::AbstractController::Base`, `::ActionCable::Engine`, `::ActionController::API`, `::ActionController::Base`, `::ActionController::Metal`, `::ActionController::Railtie`, `::ActionDispatch::Railtie`, `::ActionMailbox::Engine`, `::ActionMailer::Base`, `::ActionMailer::Preview`, `::ActionMailer::Railtie`, `::ActionText::Engine`, `::ActionView::Railtie`, `::ActionView::TestCase::TestController`, `::ActiveJob::Railtie`, `::ActiveModel::Railtie`, `::ActiveRecord::Base`, `::ActiveRecord::Railtie`, `::ActiveStorage::Engine`, `Railtie`, `::I18n::Railtie`, `::Rails::Application`, `::Rails::ApplicationController`, `::Rails::DevtoolsController`, `::Rails::Engine`, `::Rails::HealthController`, `::Rails::InfoController`, `::Rails::MailersController`, `::Rails::PwaController`, `::Rails::Railtie`, `::Rails::TestUnitRailtie`, `::Rails::WelcomeController`
Defined in:	activesupport/lib/active_support/descendants_tracker.rb

Overview

==================================

This module provides an internal implementation to track descendants which is faster than iterating through ObjectSpace.

However Ruby 3.1 provide a fast native Class#subclasses method, so if you know your code won't be executed on older rubies, including DescendantsTracker does not provide any benefit.

Class Method Summary

.descendants(klass)
.subclasses(klass)
.clear(classes) Internal use only
.disable_clear! Internal use only
.reject!(classes) Internal use only

Instance Method Summary

#descendants

Class Method Details

.clear(classes)

This method is for internal use only.

[ GitHub ]

# File 'activesupport/lib/active_support/descendants_tracker.rb', line 80


def clear(classes) # :nodoc:
  raise "DescendantsTracker.clear was disabled because config.enable_reloading is false" if @clear_disabled

  classes.each do |klass|
    @excluded_descendants << klass
    klass.descendants.each do |descendant|
      @excluded_descendants << descendant
    end
  end
end

.descendants(klass)

[ GitHub ]

# File 'activesupport/lib/active_support/descendants_tracker.rb', line 104


def descendants(klass)
  klass.descendants
end

.disable_clear!

This method is for internal use only.

[ GitHub ]

# File 'activesupport/lib/active_support/descendants_tracker.rb', line 71


def disable_clear! # :nodoc:
  unless @clear_disabled
    @clear_disabled = true
    ReloadedClassesFiltering.remove_method(:subclasses)
    ReloadedClassesFiltering.remove_method(:descendants)
    @excluded_descendants = nil
  end
end

.reject!(classes)

This method is for internal use only.

[ GitHub ]

# File 'activesupport/lib/active_support/descendants_tracker.rb', line 91


def reject!(classes) # :nodoc:
  if @excluded_descendants
    classes.reject! { |d| @excluded_descendants.include?(d) }
  end
  classes
end

.subclasses(klass)

[ GitHub ]

# File 'activesupport/lib/active_support/descendants_tracker.rb', line 100


def subclasses(klass)
  klass.subclasses
end

Instance Method Details

#descendants

[ GitHub ]

# File 'activesupport/lib/active_support/descendants_tracker.rb', line 109


def descendants
  subclasses = DescendantsTracker.reject!(self.subclasses)
  subclasses.concat(subclasses.flat_map(&:descendants))
end