Mercurial > hg > soundsoftware-site
comparison .svn/pristine/12/1274b8f28c749e735c8c75f99681e8f1e536c19a.svn-base @ 1296:038ba2d95de8 redmine-2.2
Fix redmine-2.2 branch update (add missing svn files)
author | Chris Cannam |
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date | Fri, 14 Jun 2013 09:05:06 +0100 |
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1294:3e4c3460b6ca | 1296:038ba2d95de8 |
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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 more awesome. | |
4 | |
5 Version 2 supports Rails 3. Gem versions prior to 2.0 support Rails 2. | |
6 | |
7 == What makes this so awesome? | |
8 | |
9 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. | |
10 | |
11 == Installation | |
12 | |
13 Add to your Gemfile: | |
14 | |
15 gem 'awesome_nested_set' | |
16 | |
17 == Usage | |
18 | |
19 To make use of awesome_nested_set, your model needs to have 3 fields: lft, rgt, and parent_id: | |
20 | |
21 class CreateCategories < ActiveRecord::Migration | |
22 def self.up | |
23 create_table :categories do |t| | |
24 t.string :name | |
25 t.integer :parent_id | |
26 t.integer :lft | |
27 t.integer :rgt | |
28 end | |
29 end | |
30 | |
31 def self.down | |
32 drop_table :categories | |
33 end | |
34 end | |
35 | |
36 Enable the nested set functionality by declaring acts_as_nested_set on your model | |
37 | |
38 class Category < ActiveRecord::Base | |
39 acts_as_nested_set | |
40 end | |
41 | |
42 Run `rake rdoc` to generate the API docs and see CollectiveIdea::Acts::NestedSet for more info. | |
43 | |
44 == Protecting attributes from mass assignment | |
45 | |
46 It's generally best to "white list" the attributes that can be used in mass assignment: | |
47 | |
48 class Category < ActiveRecord::Base | |
49 acts_as_nested_set | |
50 attr_accessible :name, :parent_id | |
51 end | |
52 | |
53 If for some reason that is not possible, you will probably want to protect the lft and rgt attributes: | |
54 | |
55 class Category < ActiveRecord::Base | |
56 acts_as_nested_set | |
57 attr_protected :lft, :rgt | |
58 end | |
59 | |
60 == Conversion from other trees | |
61 | |
62 Coming from acts_as_tree or another system where you only have a parent_id? No problem. Simply add the lft & rgt fields as above, and then run | |
63 | |
64 Category.rebuild! | |
65 | |
66 Your tree will be converted to a valid nested set. Awesome! | |
67 | |
68 == View Helper | |
69 | |
70 The view helper is called #nested_set_options. | |
71 | |
72 Example usage: | |
73 | |
74 <%= f.select :parent_id, nested_set_options(Category, @category) {|i| "#{'-' * i.level} #{i.name}" } %> | |
75 | |
76 <%= select_tag 'parent_id', options_for_select(nested_set_options(Category) {|i| "#{'-' * i.level} #{i.name}" } ) %> | |
77 | |
78 See CollectiveIdea::Acts::NestedSet::Helper for more information about the helpers. | |
79 | |
80 == References | |
81 | |
82 You can learn more about nested sets at: http://threebit.net/tutorials/nestedset/tutorial1.html | |
83 | |
84 == How to contribute | |
85 | |
86 If you find what you might think is a bug: | |
87 | |
88 1. Check the GitHub issue tracker to see if anyone else has had the same issue. | |
89 http://github.com/collectiveidea/awesome_nested_set/issues/ | |
90 2. If you don't see anything, create an issue with information on how to reproduce it. | |
91 | |
92 If you want to contribute an enhancement or a fix: | |
93 | |
94 1. Fork the project on github. | |
95 http://github.com/collectiveidea/awesome_nested_set/ | |
96 2. Make your changes with tests. | |
97 3. Commit the changes without making changes to the Rakefile, VERSION, or any other files that aren't related to your enhancement or fix | |
98 4. Send a pull request. | |
99 | |
100 Copyright ©2008 Collective Idea, released under the MIT license |