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README
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*******************************************************
* This is very experimental code, and has not been *
* tested on a wide range of databases. *
* *
* Please exercise caution! *
* *
* Patches and suggestions for improvement may be *
* submitted to the mailing list on rubyforge. *
*******************************************************
= acts_as_materialized_tree
Allows you to create a model which forms a "materialized tree", that is, one
where each node contains an explicit path. This allows for efficient subtree
searches [expensive in acts_as_tree] and insertion and removal of children
[expensive in acts_as_nested_set]
Requires ActiveRecord 2.1.x or later.
=== Example
In your model:
class Foo < ActiveRecord::Base
acts_as_materialized_tree
end
a = Foo.find(1)
p a.children.count # count done via SQL
p a.descendants.find(:name=>'brian') # search in subtree only
In your migration:
create_table :foos do |t|
t.string :path, :null => false, :default => ""
t.integer :next_child, :null => false, :default => 0
end
add_index :foos, :path, :unique => true
See ActiveRecord::Acts::MaterializedTree::ClassMethods and
ActiveRecord::Acts::MaterializedTree::InstanceMethods for more information.
Copyright (C) 2008 Brian Candler <B.Candler@pobox.com>. Released under the
MIT licence.