acts_as_subscribable is a small Rubygem that provides a high-level wrapper around ActiveRecord::Base to allow a model to 'subscribe' to another given model. This could be a User subscribing to a Task for example, or a Member subscribing to a Thread or even a Watcher subscribing to a Channel.

It's essentially a glorified version of a has_many :through association, but it adds a few methods to make the lookups and searching a little easier and more readable.

This is my first proper Rubygem so you'll have to bear with me on this one. If you've any suggestions of ways to improve the code, please feel free to contribute.

acts_as_subscribable was kindly funded by the marvellous Mission Control task management.

class Todo < ActiveRecord::Base
  acts_as_subscribable
end

Add it to your Gemfile:

gem 'acts_as_subscribable'

..and then bundle install. Once that's installed, we can run the built-in generator to generate our Subscription model, with an optional model name, subscribed foreign key and subscriber foreign key as parameters:

$ rails g acts_as_subscribable Subscription

This will generate our Subscription model with the appropriate migration. Run your migrations and add the acts_as_subscribable call to your model that you wish to be subscribable:

class Todo < ActiveRecord::Base
  acts_as_subscribable
end

We now have our wrapper in place. We use a bunch of sane defaults; the subscriber model defaults to User, so we'll be subscribing Users to Todos.

 > t = Todo.first
 > u = User.first
 
 > t.subscribe u
 
 > t.subscribed? u
=> true
 
 > t.subscribers
=> [ #<User id: 1 ...> ]
 
 > t.unsubscribe u
 
 > t.subscribed? u
=> false

I started writing a test suite, I promise! Just got too busy, and the metaprogramming stuff was too fiddly to test.

Copyright (c) 2011 Jamie Rumbelow, http://jamierumbelow.net

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