Nested_has_many_through is a project mainly written in Ruby, based on the MIT license.
Rails 3.x gem that allows has_many :through to go through other has_many :throughs
= NestedHasManyThrough
This gem makes it possible to define has_many :through relationships that go through other has_many :through relationships, possibly through an arbitrarily deep hierarchy. This allows associations across any number of tables to be constructed, without having to resort to find_by_sql (which isn't a suitable solution if you need to do eager loading through :include as well).
NOTE: Rails 3.x supports only. Rails 2.3 users might want to try the original nested_has_many_through[https://github.com/ianwhite/nested_has_many_through] plugin
== Intallation
Install the gem:
gem install nested_has_many_through
Add it to your gem file::
gem "nested_has_many_through"
== Usage
class Author < User
has_many :posts
has_many :categories, :through => :posts, :uniq => true
has_many :similar_posts, :through => :categories, :source => :posts
has_many :similar_authors, :through => :similar_posts, :source => :author, :uniq => true
has_many :posts_of_similar_authors, :through => :similar_authors, :source => :posts, :uniq => true
has_many :commenters, :through => :posts, :uniq => true
end
class Post < ActiveRecord::Base
belongs_to :author
belongs_to :category
has_many :comments
has_many :commenters, :through => :comments, :source => :user, :uniq => true
end
The first two has_manys of Author are plain vanilla, the last four are what this plugin enables
# has_many through a has_many :through
has_many :similar_posts, :through => :categories, :source => :posts
# doubly nested has_many :through
has_many :similar_authors, :through => :similar_posts, :source => :author, :uniq => true
# whoah!
has_many :posts_of_similar_authors, :through => :similar_authors, :source => :posts, :uniq => true
# has_many through a has_many :through in another model
has_many :commenters, :through => :posts, :uniq => true
== Maintainers
== Copyrights
This gem based on code nested_has_many_through[https://github.com/ianwhite/nested_has_many_through] plugin
MIT License. Copyright (c) 2008 Ian White - [email protected]