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.

If you pass true for the :single_root option, the class will ensure there is only ever one root in the tree.

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
Module Sequel::Plugins::Tree::SingleRoot
Class Sequel::Plugins::Tree::TreeMultipleRootError

Public Class methods

apply(model, opts=OPTS)

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

[Source]

    # File lib/sequel/plugins/tree.rb, line 32
32:       def self.apply(model, opts=OPTS)
33:         opts = opts.dup
34:         opts[:class] = model
35: 
36:         model.instance_exec do
37:           @parent_column = (opts[:key] ||= :parent_id)
38:           @tree_order = opts[:order]
39:         end
40:         
41:         par = opts.merge(opts.fetch(:parent, OPTS))
42:         parent = par.fetch(:name, :parent)
43:         
44:         chi = opts.merge(opts.fetch(:children, OPTS))
45:         children = chi.fetch(:name, :children)
46: 
47:         par[:reciprocal] = children
48:         chi[:reciprocal] = parent
49: 
50:         model.many_to_one parent, par
51:         model.one_to_many children, chi
52: 
53:         model.plugin SingleRoot if opts[:single_root]
54:       end

[Validate]