GroupedScope: Has Many Associations IN (GROUPS)
GroupedScope aims to make two things easier in your ActiveRecord models. First, provide an easy way to group objects. Second, to allow the group to share association collections via existing has_many relationships. See installation and usage for more details.
Installation & Usage
Install the gem with bundler.
To use GroupedScope on a model it must have a
class AddGroupId < ActiveRecord::Migration def up add_column :employees, :group_id, :integer end def down remove_column :employees, :group_id end end
Assume the following model.
class Employee < ActiveRecord::Base has_many :reports grouped_scope :reports end
By calling grouped_scope on any association you create a new group accessor for each instance. The object returned will act just like an array and at least include the current object that called it.
@employee_one.group # => [#<Employee id: 1, group_id: nil>]
To group resources, just assign the same
:group_id in the schema.
@employee_one.update_attribute :group_id, 1 @employee_two.update_attribute :group_id, 1 @employee_one.group # => [#<Employee id: 1, group_id: 1>, #<Employee id: 2, group_id: 1>]
Calling grouped_scope on the :reports association leaves the existing association intact.
@employee_one.reports # => [#<Report id: 2, employee_id: 1>] @employee_two.reports # => [#<Report id: 18, employee_id: 2>, #<Report id: 36, employee_id: 2>]
Now the good part, all associations passed to the grouped_scope method can be called on the group proxy. The collection will return resources shared by the group.
@employee_one.group.reports # => [#<Report id: 2, employee_id: 1>, #<Report id: 18, employee_id: 2>, #<Report id: 36, employee_id: 2>]
You can even call scopes or association extensions defined on the objects in the collection defined on the original has_many. For instance:
- Add polymorphic support.
- Add :through support.
- Raise errors and/or support :finder_sql/:counter_sql.
- Add a user definable group_id schema.
Simple! Just clone the repo, then run
bundle install and
bundle exec rake. The tests will begin to run. We also use Travis CI to run our tests too. Current build status is:
Released under the MIT license. Copyright (c) 2011 Ken Collins