lorman / parentry

ActiveRecord tree structures for PostgreSQL

Parentry

Parentry in its current incarnation is an ActiveRecord extension for the PostgreSQL ltree module.

The API is inspired by the popular ancestry gem and mirrors (with a few exceptions) the methods available in that gem.

Installation

Add this line to your application's Gemfile:

gem 'parentry'

And then execute:

$ bundle

Or install it yourself as:

$ gem install parentry

Usage

This gem requires 2 columns for each table: parentry and parent_id, and can leverage either the ltree postgresql extension, or else postgres array columns. A sample migration would look like:

enable_extension 'ltree' # ltree is not turned on by default; skip if you use the array strategy

add_column :my_table, :parent_id, :integer

add_column :my_table, :parentry, :ltree
add_column :my_table, :parentry_depth, :integer, default: 0 # optional

add_index :my_table, :parentry, using: :gist

class MyTable < ApplicationRecord
  include Parentry
  parentry cache_depth: true
  # to change strategy to array, and avoid dependency on ltree
  # parentry strategy: :array
end

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/hasghari/parentry. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.