Module: ActsAsSaneTree::ClassMethods

Defined in:
lib/acts_as_sane_tree/acts_as_sane_tree.rb

Overview

Specify this acts_as extension if you want to model a tree structure by providing a parent association and a children association. This requires that you have a foreign key column, which by default is called parent_id.

class Category < ActiveRecord::Base
  acts_as_sane_tree :order => "name"
end

Example:
root
 \_ child1
      \_ subchild1
      \_ subchild2

root      = Category.create("name" => "root")
child1    = root.children.create("name" => "child1")
subchild1 = child1.children.create("name" => "subchild1")

root.parent   # => nil
child1.parent # => root
root.children # => [child1]
root.children.first.children.first # => subchild1

The following class methods are also added:

  • nodes_within?(src, chk) - Returns true if chk contains any nodes found within src and all ancestors of nodes within src

  • nodes_within(src, chk) - Returns any matching nodes from chk found within src and all ancestors within src

  • nodes_and_descendants(*args) - Returns all nodes and descendants for given IDs or records. Accepts multiple IDs and records. Valid options:

    • :raw - No Hash nesting

    • :no_self - Will not return given nodes in result set

    • => n - Will set maximum depth to query

    • => n - Alias for :depth

    • => n - Will return times at given depth (takes precedence over :depth/:to_depth)

Instance Method Summary collapse

Instance Method Details

#acts_as_sane_tree(options = {}) ⇒ Object

Configuration options are:

  • foreign_key - specifies the column name to use for tracking of the tree (default: parent_id)

  • order - makes it possible to sort the children according to this SQL snippet.

  • counter_cache - keeps a count in a children_count column if set to true (default: false).



49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/acts_as_sane_tree/acts_as_sane_tree.rb', line 49

def acts_as_sane_tree(options = {})
  @configuration = {:foreign_key => :parent_id, :order => nil, :max_depth => 100000, :class => self, :dependent => :destroy, :parent_override => false}
  @configuration.update(options) if options.is_a?(Hash)

  self.class_eval do
    cattr_accessor :configuration
    
    has_many :children, 
      :class_name => @configuration[:class].name, 
      :foreign_key => @configuration[:foreign_key], 
      :order => @configuration[:order], 
      :dependent => @configuration[:dependent]
    belongs_to :parent, 
      :class_name => @configuration[:class].name, 
      :foreign_key => @configuration[:foreign_key]
    if(@configuration[:parent_override])
      def parent
        self.class.where(:id => self.parent_id).first
      end
    end
    
    validates_each @configuration[:foreign_key] do |record, attr, value|
      record.errors.add attr, 'cannot be own parent.' if !record.id.nil? && value.to_i == record.id.to_i
    end
  end
  self.configuration = @configuration
  include ActsAsSaneTree::InstanceMethods
  extend ActsAsSaneTree::SingletonMethods
end