From ff818e3accd8a18c58949445740a05c112a31c13 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20Ho=CC=88glund?= <jonas@stixy.com>
Date: Fri, 18 Mar 2011 09:50:34 +0100
Subject: [PATCH] Added the possibility to disable/enable PaperTrail from a
 controller

---
 README.md                                     | 11 +++++++
 lib/paper_trail.rb                            | 11 ++++++-
 lib/paper_trail/controller.rb                 | 10 ++++++-
 lib/paper_trail/has_paper_trail.rb            |  2 +-
 .../app/controllers/application_controller.rb |  1 +
 .../app/controllers/widgets_controller.rb     |  5 ++++
 test/functional/controller_test.rb            | 30 +++++++++++++++++++
 7 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 3ea15d8a..bca27e24 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,14 @@
+# Extended
+
+Added the possibility to dissable/enable PaperTrail from a controller.
+
+  class ApplicationController
+    def paper_trail_enabled_if
+      proc{ request.user_agent != 'Disabled User-Agent' }
+    end
+  end
+
+
 # PaperTrail
 
 PaperTrail lets you track changes to your models' data.  It's good for auditing or versioning.  You can see how a model looked at any stage in its lifecycle, revert it to any version, and even undelete it after it's been destroyed.
diff --git a/lib/paper_trail.rb b/lib/paper_trail.rb
index 4a437c86..1ffa7518 100644
--- a/lib/paper_trail.rb
+++ b/lib/paper_trail.rb
@@ -20,7 +20,16 @@ module PaperTrail
     !!PaperTrail.config.enabled
   end
 
-
+  # Returns if PaperTrails is disabled by controller
+  def self.request_disabled
+    paper_trail_store[:request_disabled]
+  end
+  
+  # Sets if PaperTrails is disabled by controller
+  def self.request_disabled=(value)
+    paper_trail_store[:request_disabled] = value
+  end
+  
   # Returns who is reponsible for any changes that occur.
   def self.whodunnit
     paper_trail_store[:whodunnit]
diff --git a/lib/paper_trail/controller.rb b/lib/paper_trail/controller.rb
index b4de7c4e..b517d15f 100644
--- a/lib/paper_trail/controller.rb
+++ b/lib/paper_trail/controller.rb
@@ -4,6 +4,7 @@ module PaperTrail
     def self.included(base)
       base.before_filter :set_paper_trail_whodunnit
       base.before_filter :set_paper_trail_controller_info
+      base.before_filter :set_paper_trail_enabled_if
     end
 
     protected
@@ -39,7 +40,14 @@ module PaperTrail
     end
 
     private
-
+    
+    # Tells PaperTrail if version should be saved.
+    def set_paper_trail_enabled_if
+      if respond_to? :paper_trail_enabled_if
+        ::PaperTrail.request_disabled = !paper_trail_enabled_if
+      end
+    end
+    
     # Tells PaperTrail who is responsible for any changes that occur.
     def set_paper_trail_whodunnit
       ::PaperTrail.whodunnit = user_for_paper_trail
diff --git a/lib/paper_trail/has_paper_trail.rb b/lib/paper_trail/has_paper_trail.rb
index fbc1c5cf..9443fdf1 100644
--- a/lib/paper_trail/has_paper_trail.rb
+++ b/lib/paper_trail/has_paper_trail.rb
@@ -162,7 +162,7 @@ module PaperTrail
       # Returns `true` if PaperTrail is globally enabled and active for this class,
       # `false` otherwise.
       def switched_on?
-        PaperTrail.enabled? && self.class.paper_trail_active
+        PaperTrail.enabled? && self.class.paper_trail_active && !PaperTrail.request_disabled
       end
     end
 
diff --git a/test/dummy/app/controllers/application_controller.rb b/test/dummy/app/controllers/application_controller.rb
index 41b9ce3c..29a85977 100644
--- a/test/dummy/app/controllers/application_controller.rb
+++ b/test/dummy/app/controllers/application_controller.rb
@@ -13,4 +13,5 @@ class ApplicationController < ActionController::Base
   def info_for_paper_trail
     {:ip => request.remote_ip, :user_agent => request.user_agent}
   end
+  
 end
diff --git a/test/dummy/app/controllers/widgets_controller.rb b/test/dummy/app/controllers/widgets_controller.rb
index a791580c..638c91df 100644
--- a/test/dummy/app/controllers/widgets_controller.rb
+++ b/test/dummy/app/controllers/widgets_controller.rb
@@ -1,4 +1,9 @@
 class WidgetsController < ApplicationController
+  
+  def paper_trail_enabled_if
+    request.user_agent != 'Disable User-Agent'
+  end
+  
   def create
     @widget = Widget.create params[:widget]
     head :ok
diff --git a/test/functional/controller_test.rb b/test/functional/controller_test.rb
index d9c15123..a3cdc829 100644
--- a/test/functional/controller_test.rb
+++ b/test/functional/controller_test.rb
@@ -6,6 +6,36 @@ class ControllerTest < ActionController::TestCase
   setup do
     @request.env['REMOTE_ADDR'] = '127.0.0.1'
   end
+  
+  teardown do
+    PaperTrail.request_disabled = false
+  end
+  
+  test 'disable on create' do
+    @request.env['HTTP_USER_AGENT'] = 'Disable User-Agent'
+    post :create, :widget => { :name => 'Flugel' }
+    assert_equal 0, assigns(:widget).versions.length
+  end
+  
+  test 'disable on update' do
+    @request.env['HTTP_USER_AGENT'] = 'Disable User-Agent'
+    post :create, :widget => { :name => 'Flugel' }
+    w = assigns(:widget)
+    assert_equal 0, w.versions.length
+    put :update, :id => w.id, :widget => { :name => 'Bugle' }
+    widget = assigns(:widget)
+    assert_equal 0, widget.versions.length
+  end
+  
+  test 'disable on destroy' do
+    @request.env['HTTP_USER_AGENT'] = 'Disable User-Agent'
+    post :create, :widget => { :name => 'Flugel' }
+    w = assigns(:widget)
+    assert_equal 0, w.versions.length
+    delete :destroy, :id => w.id
+    widget = assigns(:widget)
+    assert_equal 0, Version.with_item_keys('Widget', w.id).size
+  end
 
   test 'create' do
     post :create, :widget => { :name => 'Flugel' }