AclSystem2Ownership
===================

This plugin adds ownership functionality to Ezra's Zygmuntowicz acl_system plugin.
In order to use it you have to invoke 'owner' method which takes one parameter --
a string containing code that returns owner's User object. That method creates
virtual role 'owner' which you can use in your permissions strings.

Example:

class UsersController < ApplicationController
  before_filter :login_required, :only => [:update_photo]
  before_filter :find_photo   # sets @photo
  owner '@photo.user'
  access_control :update_photo => '(admin | owner)'
end

Above example gives access to users with admin role and to the owner of the
@photo object which is to be updated.

There can also be passed array of owners as owner method argument:

class UsersController < ApplicationController
  before_filter :login_required, :only => [:update_photo]
  before_filter :find_photo   # sets @photo
  owner '@users'
  access_control :update_photo => '(admin | owner)'
  
  protected
  
  def find_photo
    @photo = Photo.find(params[:id])
    @users = [@photo.owner_1, @photo.owner_2]
  end
end


page_owner
----------

There is a second virtual role added by this plugin, called 'page_owner'. It
also takes a string which returns user object as a parameter. It's sometimes
handy to have an ability to set two various users which can have access to a page
or some resources on page.
For example there are whiteboards, everybody can post new entries on them, and
authors of that entries are owners. But whiteboard belongs to one specific user
and he is the page_owner in that scenario, so:

  owner '@author', :page_owner => '@user'
  access_control :destroy => '(owner | page_owner)'

And now owner and page_owner have ability do delete whiteboard entries.


Various owners for different actions
------------------------------------

There is a possibility to define various owners for different actions:

owner '@album.user', {}, :new => '@user', :index => '@another_user', :create => '@user', :show => nil

Some actions don't have any owner, and then we can just set owners of such actions
to be nil.


TESTS
Tests won't work if acl plugin is in another directory than ../acl_system2

Author: Michal Ochman ocherek@gmail.com