forestify

forestify creates forests out of your Active Record models : it implements a simple data-structure which hierarchizes your data.

For example, given the following model :

class Tag < ActiveRecord::Base
  attr_accessible :name
  forestify
end

You can then do something like this :

# This produces the following tree
# { left_position, name, right_position, level }
# { 0, Vehicle, 9, 0 } { 10, Animal, 11, 0}
# { 1, Car, 4, 1 } { 5, Plane, 6, 1 } { 7, Boat, 8, 1 }
# { 2, Audi, 3, 2}

vehicle = Tag.create!(name: "Vehicle")
animal = Tag.create!(name: "Animal")
car = Tag.create!(name: "Car", parent_id: vehicle.id)
plane = Tag.create!(name: "plane", parent_id: vehicle.id)
boat = Tag.create!(name: "Boat", parent_id: vehicle.id)
audi = Tag.create!(name: "Audi", parent_id: car.id)

[vehicle, animal, car, plane, boat, audi].each { |n| n.reload }

audi.parents
# => [vehicle, car]
car.leaf?
# => false
car.node?
# => true
vehicle.parent.nil?
# => true
car.siblings.all
# => [plane, boat]

Installation

Run gem install forestify or add this line to your Gemfile gem 'forestify' then run bundle install

You can generate a migration to add the necessary columns to your existing models :

rails generate forestify Tag

will create the following migration :

class AddForestifyToTag < ActiveRecord::Migration

  def change
    change_table :tags do |t|
      t.integer :forestify_left_position
      t.integer :forestify_right_position
      t.integer :forestify_level
     end
  end

end

Updates

2012-02-07 version 1.0.4

• Fix migration template

2012-02-07 version 1.0.3

• Added generator documentation and updated README.

2012-02-07 version 1.0.2

• Renamed columns, added RDoc-style documentation, added migration generator.

2012-02-06 version 1.0.1

• Cleaned up tests, added two methods: 'siblings' and 'parent'

2012-02-05 version 1.0.0

• First draft

LICENSE

Copyright 2012 Gabriel Malkas. Released under MIT License. See LICENSE for details.