RESTful_ACL

RESTful_ACL is a full-stack context-based permission engine. It provides access control that is contextually aware. (If a parent is closed, a child is not editable, etc.) Permission is as simple as true or false.

Rails 3

RESTful_ACL 3.1 and on are Rails 3 ready. Rails 2 will no longer be supported. Sorries.

Requirements

RESTful_ACL requires the notion of a current_user. Most authenticaion plugins provide this (AuthLogic, RESTful_Authentication, etc.)

How to Install

Install the RESTful_ACL gem:

sudo gem install restful_acl -s http://gemcutter.org

Add the gem to your Gemfile file as thus:

gem "restful_acl"

RESTful_ACL requires a named route named "denied". Add the following to your routes.rb file:

map.denied 'denied', :controller => 'some_controller', :action => 'denied_action'

Controllers

Add before_filter :has_permission? into any controller that you'd like to restrict access to (or application_controller.rb for your entire app).

Models

Define the following five methods in the model of every resource you'd like to restrict access to. The five methods can contain anything you'd like so long as they return a boolean true or false. This allows you to define your User's roles any way you wish.

class Issue < ActiveRecord::Base

  # This method checks permissions for the :index action
  def self.is_indexable_by(user, parent = nil)
  end

  # This method checks permissions for the :create and :new action
  def self.is_creatable_by(user, parent = nil)
  end

  # This method checks permissions for the :show action
  def is_readable_by(user, parent = nil)
  end

  # This method checks permissions for the :update and :edit action
  def is_updatable_by(user, parent = nil)
  end

  # This method checks permissions for the :destroy action
  def is_deletable_by(user, parent = nil)
  end

end

Parent / Child resources

Sometimes actions should only be allowable on a resource if some "parent" resource allows them. Contextual permissions FTW.

Link your "child" resource with its "parent" resource by using the logical_parent macro and you'll have access to the "parent" resource in your child's RESTful_ACL methods.

class Child < ActiveRecord::Base
  logical_parent :parent
  ...
end

If the "child" resource is a singleton, just pass :singleton to the logical_parent macro:

class Car < ActiveRecord::Base
  logical_parent :owner, :singleton
  ...
end

View Helper

RESTful_ACL adds a view helper called allowed?. Simply pass this method a block containing the URL you'd like to check permission on and it will do the rest. The link will appear if the current_user is allowed to access the passed-in link's action.

= allowed?{ link_to ‘Foo Index’, foos_path }
= allowed?{ link_to 'Edit Foo', edit_foo_path(@foo) }
= allowed?{ link_to 'Create Foo', new_foo_path }
= allowed?{ link_to 'View Foo', foo_path(@foo) }
= allowed?{ link_to 'Delete Foo', foo_path(@foo), :method => :delete }

Huh? Here's an example

Let's say that you have two resources: Project and Issue. A Project has many Issues, an Issue belongs to a Project. I'd like to make sure that the current user is a member of the Project before they can create a new Issue in that Project:

class Issue < ActiveRecord::Base
  logical_parent :project

  belongs_to :author
  belongs_to :project

  def self.is_indexable_by(user, parent = nil)
    user.projects.include?(parent)
  end

  def self.is_creatable_by(user, parent = nil)
    user.projects.include?(parent)
  end

  def is_updatable_by(user, parent = nil)
    user == author && parent.is_active?
  end

  def is_deletable_by(user, parent = nil)
    user == author
  end

  def is_readable_by(user, parent = nil)
    user.projects.include?(parent)
  end
end

If you still have questions, please checkout the test app

Admins RULE!

RESTful_ACL grants global access to all actions to site administrators. To enable this, make sure that your User model defines an is_admin? method and/or an is_admin attribute. If the current_user.is_admin? returns true, access will be granted automatically.

How to Test

I normally do something along these lines in RSpec:

describe "Issue" do
  before do
    @project = mock_model(:project)
    @author  = mock_model(:user, :projects => [@project])
    @issue   = Factory(:issue, :author => @author, :project => @project)
  end

  it "should be modifiable by the author when the Project is active" do
    @project.stub!(:is_active? => true)
    @issue.is_updatable_by(@author, @project).should be_true
  end

  it "should be deletable by the author" do
    @issue.is_deletable_by(@author, @project).should be_true
  end

  it "should be readable by those assigned to the Project" do
    Issue.is_readable_by(@author, @project).should be_true
  end

  it "should be creatable by those assigned to the Project" do
    Issue.is_creatable_by(@author, @project).should be_true
  end
end

About the Author

My name is Matt Darby. I’m an IT Manager and pro-web-dev at for Dynamix Engineering and hold a Master’s Degree in Computer Science from Franklin University in sunny Columbus, OH.

Feel free to check out my site or recommend me