masayuki / awesome_nested_set

Fork of collectiveidea/awesome_nested_set
Description:	An awesome replacement for acts_as_nested_set and better_nested_set.
Clone URL:	git://github.com/masayuki/awesome_nested_set.git Give this clone URL to anyone. `git clone git://github.com/masayuki/awesome_nested_set.git`

Changed method of deletion used in prune. This way the correct callbacks 
are carried out on all descendants when pruning occurs. It is useful to 
have callbacks occurring so that things like HABTM associations can be 
severed first to prevent DB crufting without reinventing the wheel with 
observers.

masayuki (author)

Tue Jun 10 09:07:13 -0700 2008

commit 7ee6385bb169edcfbfb02d5d921380478acaca95
tree 2d563796e06dc5790452eca5732ef9cdb53540bc
parent 38445c4cf7fe72ef48017b663b62573003a365c7

awesome_nested_set /

name	age	history message
.gitignore	Sat Jun 07 21:02:49 -0700 2008	added rake test:coverage task [brandon]
MIT-LICENSE	Thu Oct 18 06:46:41 -0700 2007	new implementation of nested set based off of b... [brandon]
README.rdoc	Mon Jun 09 10:15:01 -0700 2008	Added revised callbacks around add_to_child. Te... [masayuki]
Rakefile	Sat Jun 07 21:02:49 -0700 2008	added rake test:coverage task [brandon]
init.rb	Sat May 17 12:44:32 -0700 2008	added named_scope from edge rails and re-wrote ... [brandon]
lib/	Tue Jun 10 09:07:13 -0700 2008	Changed method of deletion used in prune. This ... [masayuki]
test/	Mon Jun 09 10:20:42 -0700 2008	removed test code than exposed protected method... [masayuki]

README.rdoc

AwesomeNestedSet

Awesome Nested Set is an implementation of the nested set pattern for ActiveRecord models. It is replacement for acts_as_nested_set and BetterNestedSet, but awesomer.

What makes this so awesome?

This is a new implementation of nested set based off of BetterNestedSet that fixes some bugs, removes tons of duplication, adds a few useful methods, callbacks, adds STI support and adds 2 very helpful view helpers for select boxes.

Installation

If you are on edge rails:

  script/plugin install git://github.com/collectiveidea/awesome_nested_set.git

If you are not on edge rails:

  git clone git://github.com/collectiveidea/awesome_nested_set.git vendor/plugins/awesome_nested_set

Usage

To make use of awesome_nested_set, your model needs to have 3 fields: lft, rgt, and parent_id:

  class CreateCategories < ActiveRecord::Migration
    def self.up
      create_table :categories do |t|
        t.string :name
        t.integer :parent_id
        t.integer :lft
        t.integer :rgt
      end
    end

    def self.down
      drop_table :categories
    end
  end

Enable the nested set functionality by declaring acts_as_nested_set on your model

  class Category < ActiveRecord::Base
    acts_as_nested_set
  end

Run `rake rdoc` to generate the API docs and see CollectiveIdea::Acts::NestedSet::SingletonMethods for more info.

View Helpers

#nested_set_options_for_select - returns an array of objects suitable for select helpers
#nested_set_options_for_select_without_impossible_moves - similar to nested_set_options_for_select, but contains only items that are possible to move to

See CollectiveIdea::Acts::NestedSet::Helper for more information about the helpers.

References

You can learn more about nested sets at:

  http://www.dbmsmag.com/9603d06.html
  http://threebit.net/tutorials/nestedset/tutorial1.html
  http://api.rubyonrails.com/classes/ActiveRecord/Acts/NestedSet/ClassMethods.html
  http://opensource.symetrie.com/trac/better_nested_set/