https://github.com/ledermann/redundant_links

Automatic handling of a join table for indirect (transitive) associations.
https://github.com/ledermann/redundant_links

Last synced: over 1 year ago
JSON representation

Automatic handling of a join table for indirect (transitive) associations.

• Host: GitHub
• URL: https://github.com/ledermann/redundant_links
• Owner: ledermann
• License: mit
• Created: 2008-10-29T16:31:14.000Z (over 17 years ago)
• Default Branch: master
• Last Pushed: 2011-04-10T06:05:08.000Z (about 15 years ago)
• Last Synced: 2025-02-15T18:54:22.354Z (over 1 year ago)
• Language: Ruby
• Homepage:
• Size: 113 KB
• Stars: 2
• Watchers: 4
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README
  • License: MIT-LICENSE

Awesome Lists containing this project

README

          
redundant_links

===============

Automatic handling of a join table for indirect associations

Plugin for Ruby on Rails 2.1 (or newer)

Example

=======

Assume you have contacts who can place multiple orders. In addition, contacts 

and orders may have multiple notes. This plugin helps you to get the notes

of a contact, even if they belong to one of its orders. This is just a simple

example. Of course it works in more complex situations, too.

class Contact < ActiveRecord::Base

  has_many :orders

  has_many :notes, :as => :object

end

class Order < ActiveRecord::Base

  belongs_to :contact

  has_many :notes, :as => :object

end

class Note < ActiveRecord::Base

  belongs_to :object, :polymorphic => true

  

  has_redundant_links Note    => :object, 

                      Order   => :contact, 

                      Contact => nil

end

contact = Contact.find(123)

Now you can do:

With plain Rails magic:

contact.notes

=> Gives you only the notes which directly belong to the contact

With this plugin:

contact.redundant_linked_notes

=> Gives you the notes which either directly belong to the contact or 

   belong to orders of this contact

How it works

============

The plugin manages a join table named "redundant_links" with all direct and

indirect associations between a detail model and defined master models. It

creates an instance method in all of the master models to get the linked

detail records (based on a simple INNER JOIN, so it's quite fast).

Installation

============

script/plugin install git://github.com/ledermann/redundant_links.git

script/generate redundant_link_migration add_redundant_links_table

rake db:migrate

Usage

=====

In your detail model place this

  has_redundant_links(options)

See the source code for more information about the options hash.

ToDo

====

- Some optimizations, so updating join table records is only made if it's needed

Copyright (c) 2008 Georg Ledermann, released under the MIT license