Store controller info. Allow other current_user methods.

PaperTrail can now store any information from the controller or request.
It's also easy to choose a method other than `current_user` for
PaperTrail to call to find out who was responsible for changes.

README.md

@@ -11,9 +11,10 @@ PaperTrail lets you track changes to your models' data.  It's good for auditing
 * Allows you to get at every version, including the original, even once destroyed.
 * Allows you to get at every version even if the schema has since changed.
 * Allows you to get at the version as of a particular time.
-* Automatically records who was responsible if your controller has a `current_user` method.
+* Automatically records who was responsible via your controller.  PaperTrail calls `current_user` by default, if it exists, but you can have it call any method you like.
 * Allows you to set who is responsible at model-level (useful for migrations).
-* Allows you to store arbitrary metadata with each version (useful for filtering versions).
+* Allows you to store arbitrary model-level metadata with each version (useful for filtering versions).
+* Allows you to store arbitrary controller-level information with each version, e.g. remote IP.
 * Can be turned off/on per class (useful for migrations).
 * Can be turned off/on globally (useful for testing).
 * No configuration necessary.
@@ -146,6 +147,14 @@ If your `ApplicationController` has a `current_user` method, PaperTrail will sto
     >> last_change = Widget.versions.last
     >> user_who_made_the_change = User.find last_change.whodunnit.to_i
 
+You may want PaperTrail to call a different method to find out who is responsible.  To do so, override the `user_for_paper_trail` method in your controller like this:
+
+    class ApplicationController
+      def user_for_paper_trail
+        logged_in? ? current_member : 'Public user'  # or whatever
+      end
+    end
+
 In a migration or in `script/console` you can set who is responsible like this:
 
     >> PaperTrail.whodunnit = 'Andy Stewart'
@@ -155,7 +164,7 @@ In a migration or in `script/console` you can set who is responsible like this:
 
 ## Storing metadata
 
-You can store arbitrary metadata alongside each version like this:
+You can store arbitrary model-level metadata alongside each version like this:
 
     class Article < ActiveRecord::Base
       belongs_to :author
@@ -169,6 +178,16 @@ Why would you do this?  In this example, `author_id` is an attribute of `Article
 
     Version.all(:conditions => ['author_id = ?', author_id])
 
+You can also store any information you like from your controller.  Just override the `info_for_paper_trail` method in your controller to return a hash whose keys correspond to columns in your `versions` table.  E.g.:
+
+    class ApplicationController
+      def info_for_paper_trail
+        { :ip => request.remote_ip, :user_agent => request.user_agent }
+      end
+    end
+
+Remember to add those extra columns to your `versions` table ;)
+
 
 ## Turning PaperTrail Off/On
 

lib/paper_trail.rb

@@ -18,14 +18,10 @@ module PaperTrail
     !!PaperTrail.config.enabled
   end
 
-  # Returns PaperTrail's configuration object.
-  def self.config
-    @@config ||= PaperTrail::Config.instance
-  end
 
   # Returns who is reponsible for any changes that occur.
   def self.whodunnit
-    Thread.current[:whodunnit]
+    paper_trail_store[:whodunnit]
   end
 
   # Sets who is responsible for any changes that occur.
@@ -33,7 +29,36 @@ module PaperTrail
   # when working with models directly.  In a controller it is set
   # automatically to the `current_user`.
   def self.whodunnit=(value)
-    Thread.current[:whodunnit] = value
+    paper_trail_store[:whodunnit] = value
+  end
+
+  # Returns any information from the controller that you want
+  # PaperTrail to store.
+  #
+  # See `PaperTrail::Controller#info_for_paper_trail`.
+  def self.controller_info
+    paper_trail_store[:controller_info]
+  end
+
+  # Sets any information from the controller that you want PaperTrail
+  # to store.  By default this is set automatically by a before filter.
+  def self.controller_info=(value)
+    paper_trail_store[:controller_info] = value
+  end
+
+
+  private
+
+  # Thread-safe hash to hold PaperTrail's data.
+  #
+  # TODO: is this a memory leak?
+  def self.paper_trail_store
+    Thread.current[:paper_trail] ||= {}
+  end
+
+  # Returns PaperTrail's configuration object.
+  def self.config
+    @@config ||= PaperTrail::Config.instance
   end
 
 end

lib/paper_trail/controller.rb

@@ -2,15 +2,59 @@ module PaperTrail
   module Controller
 
     def self.included(base)
-      base.before_filter :set_whodunnit
+      base.before_filter :set_paper_trail_whodunnit
+      base.before_filter :set_paper_trail_controller_info
     end
 
     protected
 
-    # Sets who is responsible for any changes that occur: the controller's
-    # `current_user`.
+    # Returns the user who is responsible for any changes that occur.
+    # By default this calls `current_user` and returns the result.
+    # 
+    # Override this method in your controller to call a different
+    # method, e.g. `current_person`, or anything you like.
+    def user_for_paper_trail
+      current_user rescue nil
+    end
+
+    # Returns any information about the controller or request that you
+    # want PaperTrail to store alongside any changes that occur.  By
+    # default this returns an empty hash.
+    #
+    # Override this method in your controller to return a hash of any
+    # information you need.  The hash's keys must correspond to columns
+    # in your `versions` table, so don't forget to add any new columns
+    # you need.
+    #
+    # For example:
+    #
+    #     {:ip => request.remote_ip, :user_agent => request.user_agent}
+    #
+    # The columns `ip` and `user_agent` must exist in your `versions` # table.
+    #
+    # Use the `:meta` option to `PaperTrail::Model::ClassMethods.has_paper_trail`
+    # to store any extra model-level data you need.
+    def info_for_paper_trail
+      {}
+    end
+
+    private
+
+    # Tells PaperTrail who is responsible for any changes that occur.
+    def set_paper_trail_whodunnit
+      ::PaperTrail.whodunnit = user_for_paper_trail
+    end
+
+    # DEPRECATED: please use `set_paper_trail_whodunnit` instead.
     def set_whodunnit
-      ::PaperTrail.whodunnit = self.send :current_user rescue nil
+      logger.warn '[PaperTrail]: the `set_whodunnit` controller method has been deprecated.  Please rename to `set_paper_trail_whodunnit`.'
+      set_paper_trail_whodunnit
+    end
+
+    # Tells PaperTrail any information from the controller you want
+    # to store alongside any changes that occur.
+    def set_paper_trail_controller_info
+      ::PaperTrail.controller_info = info_for_paper_trail
     end
 
   end

lib/paper_trail/has_paper_trail.rb

@@ -7,11 +7,16 @@ module PaperTrail
 
 
     module ClassMethods
+
+      # Declare this in your model to track every create, update, and destroy.  Each version of
+      # the model is available in the `versions` association.
+      #
       # Options:
-      # :ignore    an array of attributes for which a new +Version+ will not be created if only they change.
-      # :meta      a hash of extra data to store.  You must add a column to the versions table for each key.
-      #            Values are objects or procs (which are called with +self+, i.e. the model with the paper
-      #            trail).
+      # :ignore    an array of attributes for which a new `Version` will not be created if only they change.
+      # :meta      a hash of extra data to store.  You must add a column to the `versions` table for each key.
+      #            Values are objects or procs (which are called with `self`, i.e. the model with the paper
+      #            trail).  See `PaperTrail::Controller.info_for_paper_trail` for how to store data from
+      #            the controller.
       def has_paper_trail(options = {})
         send :include, InstanceMethods
 
@@ -83,10 +88,12 @@ module PaperTrail
       private
 
       def merge_metadata(data)
+        # First we merge the model-level metadata in `meta`.
         meta.each do |k,v|
           data[k] = v.respond_to?(:call) ? v.call(self) : v
         end
-        data
+        # Second we merge any extra data from the controller (if available).
+        data.merge(PaperTrail.controller_info || {})
       end
 
       def previous_version

test/paper_trail_controller_test.rb

@@ -13,6 +13,10 @@ class ApplicationController < ActionController::Base
   def current_user
     153
   end
+
+  def info_for_paper_trail
+    {:ip => request.remote_ip, :user_agent => request.user_agent}
+  end
 end
 
 class WidgetsController < ApplicationController
@@ -37,11 +41,17 @@ end
 class PaperTrailControllerTest < ActionController::TestCase
   tests WidgetsController
 
+  def setup
+    @request.env['REMOTE_ADDR'] = '127.0.0.1'
+  end
+
   test 'create' do
     post :create, :widget => { :name => 'Flugel' }
     widget = assigns(:widget)
     assert_equal 1, widget.versions.length
     assert_equal 153, widget.versions.last.whodunnit.to_i
+    assert_equal '127.0.0.1', widget.versions.last.ip
+    assert_equal 'Rails Testing', widget.versions.last.user_agent
   end
 
   test 'update' do
@@ -51,6 +61,8 @@ class PaperTrailControllerTest < ActionController::TestCase
     widget = assigns(:widget)
     assert_equal 2, widget.versions.length
     assert_equal 153, widget.versions.last.whodunnit.to_i
+    assert_equal '127.0.0.1', widget.versions.last.ip
+    assert_equal 'Rails Testing', widget.versions.last.user_agent
   end
 
   test 'destroy' do
@@ -60,5 +72,7 @@ class PaperTrailControllerTest < ActionController::TestCase
     widget = assigns(:widget)
     assert_equal 2, widget.versions.length
     assert_equal 153, widget.versions.last.whodunnit.to_i
+    assert_equal '127.0.0.1', widget.versions.last.ip
+    assert_equal 'Rails Testing', widget.versions.last.user_agent
   end
 end

test/schema.rb

@@ -27,6 +27,10 @@ ActiveRecord::Schema.define(:version => 0) do
     t.integer :answer
     t.string  :question
     t.integer :article_id
+
+    # Controller info columns.
+    t.string :ip
+    t.string :user_agent
   end
   add_index :versions, [:item_type, :item_id]
 

test/test_helper.rb

@@ -34,4 +34,10 @@ class ActiveRecord::Base
   end
 end
 
+class ActionController::Base
+  def logger
+    @logger ||= Logger.new(nil)
+  end
+end
+
 load_schema