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This Rails plugin extends ActiveRecord::Base to add automatic updating of created_by and updated_by attributes of your models in much the same way that the ActiveRecord::Timestamp module updates created_(at/on) and updated_(at/on) attributes.
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Userstamp Plugin (v 2.0)

The Userstamp Plugin extends ActiveRecord::Base(
to add automatic updating of 'creator', 'updater', and 'deleter' attributes. It is based loosly on the
ActiveRecord::Timestamp( module.

Two 'act_as' class methods are available with this plugin and are required on each of the objects wanting
to gain this functionality. These two methods are: 'acts_as_stamper' and 'acts_as_stampable'. ActsAsStamper
should be used with objects that are responsible for creating, updating, or deleting other objects.
ActsAsStampable should be use with objects that are subject to being created, updated, or deleted by 'stampers'.

Installation of the plugin can be done using the built in Rails plugin script. Issue the following command
from the root of your application:

script/plugin install svn:// userstamp

Once installed you will need to restart your webserver for the plugin to be loaded into the Rails environment.

You might also be interested in using Piston( to manage the importing
and future updating of this plugin.

In version 2 of the Userstamp plug-in, there is now the assumption that you have two different categories of
objects; those that manimpulate, and those that are manipulated. For those objects that are being manipulated
we have ActsAsStampable and for the manipulators we have ActsAsStamper. There's also a module for your
controllers that assists in setting up your environment on a per request basis. To better understand how all
this works, I think an example is in order. For this example we will assume that we are creating a weblog
application that is comprised of User and Post objects. Since Users manipulate Posts, we'll do the following:

class User < ActiveRecord::Base

And Posts are manipulated by Users, so it should look like this:

class Post < ActiveRecord::Base

Then the final piece is the Userstamp module that should be included into a controller
(the ApplicationController is recommended):

class ApplicationController < ActionController::Base
  include Userstamp

So, what did we just do here? Well, the acts_as_stamper class method injects two methods into the User class.
They are #stamper= and #stamper and look like this:

def stamper=(object)
  Thread.current["#{self.to_s.downcase}_#{self.object_id}_stamper"] = object.is_a?(ActiveRecord::Base) ?
                                                                                    object.send("#{object.class.primary_key}".to_sym) :

def stamper

With the setter method you can see that we test if the passed in object is a descendant of ActiveRecord.
If it is we get the value of it's primary key attribute, otherwise we just use the object as is. You'll also
notice that we store this value using Thread.current, so as to avoid conflict with colliding requests.

The Userstamp module that we included into our ApplicationController uses the setter method to tell the
application which user is currently in use. By default the 'set_stampers' method looks like this:

def set_stampers
  User.stamper = self.current_user

You should redefine this method to suite your particular application, but if you are using the ActsAsAuthenticated
plugin, the module's implementation works just fine out of the box.

Now, let's get back to ActsAsStampable (since it really is the interesting one). If you've already created your
database with columns called 'creator_id', 'updater_id' and 'deleter_id', and you're Stamper object is 'User' than
your set and ready to go. ActsAsStampable sets up before_* filters that are responsible for setting those attributes
at the appropriate times. It also creates the belongs_to relationships for you. If you need to use something different
the method can be completely customized. For example, here's how one would upgrade from version 1 of the plugin:

class Post < ActiveRecord::Base
  acts_as_stampable :stamper_class_name => :person,
                    :creator_attribute  => :created_by,
                    :updater_attribute  => :updated_by,
                    :deleter_attribute  => :deleted_by

Uninstalling the plugin can be done using the built in Rails plugin script. Issue the following command from the root
of your application:

script/plugin remove userstamp

RDoc has been run on the plugin directory and is available in the doc directory. You can also view the documentation
online at:

Running Unit Tests
There are extensive unit tests in the "test" directory of the plugin. 

Bugs & Feedback
Bug reports and feedback are always welcome. Please send them to with [Userstamp] in the subject line.

Credits and Special Thanks
The original idea for this plugin came from the Rails Wiki article entitled
"Extending ActiveRecord" (
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