Skip to content
This repository


Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP

Enhances ActiveRecord with nested hierarchies.

branch: master


Gem Version Code Climate GPA Gemnasium Status Travis CI Status Coverage Status

A implementation of the Closure Table pattern for ActiveRecord models. This uses two tables to maintain the ancestor/descendant relationship for all branches of a particular model. For example, you might have web pages you want to represent in a nested hierarchy which would yield the following table structure:

  • Page (i.e. pages)
  • PageBranch (i.e. page_branches)

Assuming the following page hierarchy:

Branch Graph

The page_branches table would consiste of the following data:

Branch Table


  • Database integrity via the Closure Table pattern.


  1. Any of the following Ruby VMs:
  2. Ruby on Rails 4.x.x.


For a secure install, type the following from the command line (recommended):

gem cert --add <(curl -Ls
gem install lineage --trust-policy MediumSecurity

NOTE: A HighSecurity trust policy would be best but MediumSecurity enables signed gem verification while allowing the installation of unsigned dependencies since they are beyond the scope of this gem.

For an insecure install, type the following (not recommended):

gem install lineage

Add the following to your Gemfile:

gem "lineage"


Add the following to any model you wish to enable with lineage support:



To test, do the following:

  1. cd to the gem root.
  2. bundle install
  3. bundle exec rspec spec


Read Semantic Versioning for details. Briefly, it means:

  • Patch (x.y.Z) - Incremented for small, backwards compatible bug fixes.
  • Minor (x.Y.z) - Incremented for new, backwards compatible public API enhancements and/or bug fixes.
  • Major (X.y.z) - Incremented for any backwards incompatible public API changes.


Read CONTRIBUTING for details.


Developed by Brooke Kuhlmann at Red Alchemist


Copyright (c) 2010 Red Alchemist. Read the LICENSE for details.


Read the CHANGELOG for details. Built with Gemsmith.

Something went wrong with that request. Please try again.