comparison vendor/plugins/awesome_nested_set/.svn/text-base/README.rdoc.svn-base @ 0:513646585e45

* Import Redmine trunk SVN rev 3859
author Chris Cannam
date Fri, 23 Jul 2010 15:52:44 +0100
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1 = AwesomeNestedSet
2
3 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.
4
5 == What makes this so awesome?
6
7 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, and adds STI support.
8
9 == Installation
10
11 If you are on Rails 2.1 or later:
12
13 script/plugin install git://github.com/collectiveidea/awesome_nested_set.git
14
15 == Usage
16
17 To make use of awesome_nested_set, your model needs to have 3 fields: lft, rgt, and parent_id:
18
19 class CreateCategories < ActiveRecord::Migration
20 def self.up
21 create_table :categories do |t|
22 t.string :name
23 t.integer :parent_id
24 t.integer :lft
25 t.integer :rgt
26 end
27 end
28
29 def self.down
30 drop_table :categories
31 end
32 end
33
34 Enable the nested set functionality by declaring acts_as_nested_set on your model
35
36 class Category < ActiveRecord::Base
37 acts_as_nested_set
38 end
39
40 Run `rake rdoc` to generate the API docs and see CollectiveIdea::Acts::NestedSet::SingletonMethods for more info.
41
42 == View Helper
43
44 The view helper is called #nested_set_options.
45
46 Example usage:
47
48 <%= f.select :parent_id, nested_set_options(Category, @category) {|i| "#{'-' * i.level} #{i.name}" } %>
49
50 <%= select_tag 'parent_id', options_for_select(nested_set_options(Category) {|i| "#{'-' * i.level} #{i.name}" } ) %>
51
52 See CollectiveIdea::Acts::NestedSet::Helper for more information about the helpers.
53
54 == References
55
56 You can learn more about nested sets at:
57
58 http://www.dbmsmag.com/9603d06.html
59 http://threebit.net/tutorials/nestedset/tutorial1.html
60 http://api.rubyonrails.com/classes/ActiveRecord/Acts/NestedSet/ClassMethods.html
61 http://opensource.symetrie.com/trac/better_nested_set/
62
63
64 Copyright (c) 2008 Collective Idea, released under the MIT license