h2. RESTful_ACL
A Ruby on Rails plugin that provides fine grained access control through the MVC stack to RESTful resources in a Ruby on Rails 2.0+ application. Authorization is as simple as true or false.
h3. What it does
RESTful_ACL is a simple Access Control Layer for Ruby on Rails. It restricts access on a fine-grained level to any RESTful MVC stack. Every application is different and everyone likes to setup their User / Account / Role resources differently; this plugin will allow you to do your thing and keep that thing locked down.
h3. Requirements
RESTful_ACL requires the super amazing "RESTful_Authentication":https://github.com/technoweenie/restful-authentication plugin.
h3. How to Install
Install the RESTful_ACL gem:
sudo gem install mdarby-restful_acl -s http://gems.github.com
Add the gem to your environment.rb file as thus:
config.gem "mdarby-restful_acl", :lib => 'restful_acl_controller'
RESTful_ACL requires two named routes: "error" and "denied". Add the following to your routes.rb file:
map.error '/error', :controller => 'some_controller', :action => 'error_action'
map.denied '/denied', :controller => 'some_controller', :action => 'denied_action'
h3. How to Use
h4. 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).
h4. Models
Define a parent resource (if one exists) by using the @logical_parent@ method, and 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
logical_parent :some_model_name
# 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
h4. View Helpers
There are five view helpers also included in RESTful_ACL: @#indexable@, @#creatable@, @#readable@, @#updatable@, and @#deletable@. These enable you to do nifty things like:
<%= link_to ‘Foo Index’, foos_path if indexable %>
<%= link_to 'Edit Foo', edit_foo_path(@foo) if updatable(@foo) %>
<%= link_to 'Create Foo', new_foo_path if creatable %>
<%= link_to 'View Foo', foo_path(@foo) if readable(@foo) %>
<%= link_to 'Delete Foo', foo_path(@foo) if deletable(@foo), :method => :destroy %>
h3. 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
h3. 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.
h3. 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 = Issue.factory_girl(: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
h3. Caveats
RESTful_ACL doesn't work with nested singleton resources. Wha? Yeah. Those are things in routes.rb like:
# Note the singular forms in 'user.resource :profile'
map.resources :users do |user|
user.resource :profile
end
In these situations I normally skip permission checking altogether as a Profile will always be mapped to the currently logged in User, regardless of the @params[:user_id]@ passed in. You don't trust those either right? Good.
h3. Help
Add a ticket to "RESTful_ACL's Lighthouse Account":http://mdarby.lighthouseapp.com/projects/28698-restful_acl/overview
h3. About the Author
My name is "Matt Darby.":http://blog.matt-darby.com I’m an IT Manager and pro-web-dev at for "Dynamix Engineering":http://dynamix-ltd.com and hold a Master’s Degree in Computer Science from "Franklin University":http://www.franklin.edu in sunny "Columbus, OH.":http://en.wikipedia.org/wiki/Columbus,_Ohio
Feel free to check out my "blog":http://blog.matt-darby.com or "recommend me":http://www.workingwithrails.com/person/10908-matt-darby