Module Sequel::Plugins::Tree
In: lib/sequel/plugins/tree.rb

The Tree plugin adds additional associations and methods that allow you to treat a Model as a tree.

A column for holding the parent key is required and is :parent_id by default. This may be overridden by passing column name via :key

Optionally, a column to control order of nodes returned can be specified by passing column name via :order.

Examples:

  class Node < Sequel::Model
    plugin :tree
  end

  class Node < Sequel::Model
    plugin :tree, :key=>:parentid, :order=>:position
  end

Methods

apply  

Classes and Modules

Module Sequel::Plugins::Tree::ClassMethods
Module Sequel::Plugins::Tree::InstanceMethods

Public Class methods

Create parent and children associations. Any options specified are passed to both associations. You can specify options to use for the parent association using a :parent option, and options to use for the children association using a :children option.

[Source]

    # File lib/sequel/plugins/tree.rb, line 27
27:       def self.apply(model, opts={})
28:         opts = opts.dup
29:         opts[:class] = model
30: 
31:         model.instance_eval do
32:           @parent_column = (opts[:key] ||= :parent_id)
33:           @tree_order = opts[:order]
34:         end
35:         
36:         par = opts.merge(opts.fetch(:parent, {}))
37:         parent = par.fetch(:name, :parent)
38:         model.many_to_one parent, par
39:         
40:         chi = opts.merge(opts.fetch(:children, {}))
41:         children = chi.fetch(:name, :children)
42:         model.one_to_many children, chi
43:       end

[Validate]