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.
http://metaskills.net/2008/09/28/jack-has_many-things/
Install the gem with bundler.
gem 'grouped_scope'
To use GroupedScope on a model it must have a :group_id
column.
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:
@employee.group.reports.urgent.assigned_to(user)
- Add more GroupedScope::Grouping code.
- 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