Allows the definition of a customized whodunnit in a small scope

README.md

@@ -57,7 +57,7 @@ The Rails 2.3 code is on the [`rails2`](https://github.com/airblade/paper_trail/
 ### Sinatra
 
 In order to configure `PaperTrail` for usage with [Sinatra](http://www.sinatrarb.com),
-your `Sinatra` app must be using `ActiveRecord` 3 or  `ActiveRecord` 4. It is also recommended to use the 
+your `Sinatra` app must be using `ActiveRecord` 3 or  `ActiveRecord` 4. It is also recommended to use the
 [Sinatra ActiveRecord Extension](https://github.com/janko-m/sinatra-activerecord) or something similar for managing
 your applications `ActiveRecord` connection in a manner similar to the way `Rails` does. If using the aforementioned
 `Sinatra ActiveRecord Extension`, steps for setting up your app with `PaperTrail` will look something like this:
@@ -489,6 +489,21 @@ class PaperTrail::Version < ActiveRecord::Base
 end
 ```
 
+Sometimes you want to define who is responsible in a small scope and don't using `PaperTrail.whodunnit`. In these cases it is possible to define executing your operation inside a block:
+
+```ruby
+PaperTrail.whodunnit = 'Andy Stewart'
+
+widget.whodunnit 'Lucas Souza' do
+  widget.update_attributes :name => 'Wibble'
+end
+
+widget.versions.last.whodunnit              # Lucas Souza
+
+widget.update_attributes :name => 'Clair'
+widget.versions.last.whodunnit              # Andy Stewart
+```
+
 A version's `whodunnit` records who changed the object causing the `version` to be stored.  Because a version stores the object as it looked before the change (see the table above), `whodunnit` returns who stopped the object looking like this -- not who made it look like this.  Hence `whodunnit` is aliased as `terminator`.
 
 To find out who made a version's object look that way, use `version.originator`.  And to find out who made a "live" object look like it does, use `originator` on the object.

lib/paper_trail/has_paper_trail.rb

@@ -14,11 +14,11 @@ module ClassMethods
       #               `:create`, `:update`, `:destroy` as desired.
       # :class_name   the name of a custom Version class.  This class should inherit from `PaperTrail::Version`.
       # :ignore       an array of attributes for which a new `Version` will not be created if only they change.
-      #               it can also aceept a Hash as an argument where the key is the attribute to ignore (a `String` or `Symbol`), 
+      #               it can also aceept a Hash as an argument where the key is the attribute to ignore (a `String` or `Symbol`),
       #               which will only be ignored if the value is a `Proc` which returns truthily.
       # :if, :unless  Procs that allow to specify conditions when to save versions for an object
       # :only         inverse of `ignore` - a new `Version` will be created only for these attributes if supplied
-      #               it can also aceept a Hash as an argument where the key is the attribute to track (a `String` or `Symbol`), 
+      #               it can also aceept a Hash as an argument where the key is the attribute to track (a `String` or `Symbol`),
       #               which will only be counted if the value is a `Proc` which returns truthily.
       # :skip         fields to ignore completely.  As with `ignore`, updates to these fields will not create
       #               a new `Version`.  In addition, these fields will not be included in the serialized versions
@@ -232,6 +232,11 @@ def touch_with_version(name = nil)
         save!
       end
 
+      def whodunnit(whodunnit)
+        @whodunnit = whodunnit
+        yield if block_given?
+      end
+
       private
 
       def source_version
@@ -242,13 +247,16 @@ def record_create
         if paper_trail_switched_on?
           data = {
             :event     => paper_trail_event || 'create',
-            :whodunnit => PaperTrail.whodunnit
+            :whodunnit => _whodunnit
           }
 
           if changed_notably? and self.class.paper_trail_version_class.column_names.include?('object_changes')
             data[:object_changes] = self.class.paper_trail_version_class.object_changes_col_is_json? ? changes_for_paper_trail :
               PaperTrail.serializer.dump(changes_for_paper_trail)
           end
+
+          clean_whodunnit
+
           send(self.class.versions_association_name).create! merge_metadata(data)
         end
       end
@@ -259,12 +267,15 @@ def record_update
           data = {
             :event     => paper_trail_event || 'update',
             :object    => self.class.paper_trail_version_class.object_col_is_json? ? object_attrs : PaperTrail.serializer.dump(object_attrs),
-            :whodunnit => PaperTrail.whodunnit
+            :whodunnit => _whodunnit
           }
           if self.class.paper_trail_version_class.column_names.include?('object_changes')
             data[:object_changes] = self.class.paper_trail_version_class.object_changes_col_is_json? ? changes_for_paper_trail :
               PaperTrail.serializer.dump(changes_for_paper_trail)
           end
+
+          clean_whodunnit
+
           send(self.class.versions_association_name).build merge_metadata(data)
         end
       end
@@ -283,13 +294,17 @@ def record_destroy
             :item_type => self.class.base_class.name,
             :event     => paper_trail_event || 'destroy',
             :object    => self.class.paper_trail_version_class.object_col_is_json? ? object_attrs : PaperTrail.serializer.dump(object_attrs),
-            :whodunnit => PaperTrail.whodunnit
+            :whodunnit => _whodunnit
           }
           self.class.paper_trail_version_class.create merge_metadata(data)
           send(self.class.versions_association_name).send :load_target
         end
       end
 
+      def clean_whodunnit
+        @whodunnit = nil
+      end
+
       def merge_metadata(data)
         # First we merge the model-level metadata in `meta`.
         paper_trail_options[:meta].each do |k,v|
@@ -362,6 +377,10 @@ def save_version?
         unless_condition = self.paper_trail_options[:unless]
         (if_condition.blank? || if_condition.call(self)) && !unless_condition.try(:call, self)
       end
+
+      def _whodunnit
+        @whodunnit || PaperTrail.whodunnit
+      end
     end
   end
 end

test/unit/model_test.rb

@@ -535,6 +535,66 @@ def without(&block)
       @widget = Widget.new :name => 'Fidget'
     end
 
+    context 'defining whodunnit using a block' do
+      context "when a record is created" do
+        setup do
+          PaperTrail.whodunnit = 'Helena'
+
+          @widget.whodunnit 'Clair' do
+            @widget.save
+          end
+
+          @version = @widget.versions.last  # only 1 version
+        end
+
+        should 'track who made the change' do
+          assert_equal 'Clair', @version.whodunnit
+        end
+
+        should 'ignore defined whodunnit using global whodunnit' do
+          @widget.update_attributes :name => 'Fernandes'
+          @version = @widget.versions.last
+
+          assert_equal 'Helena', @version.whodunnit
+        end
+
+        context "when a record is updated" do
+          setup do
+            @widget.whodunnit 'Rafaela' do
+              @widget.update_attributes :name => 'Fernandes'
+            end
+
+            @version = @widget.versions.last  # only 1 version
+          end
+
+          should 'track who made the change' do
+            assert_equal 'Rafaela', @version.whodunnit
+          end
+
+          should 'ignore defined whodunnit using global whodunnit' do
+            @widget.update_attributes :name => 'Souza'
+            @version = @widget.versions.last
+
+            assert_equal 'Helena', @version.whodunnit
+          end
+        end
+
+        context 'when a record is destroyed' do
+          setup do
+            @widget.whodunnit 'Lucas' do
+              @widget.destroy
+            end
+
+            @version = PaperTrail::Version.last
+          end
+
+          should 'track who made the change' do
+            assert_equal 'Lucas', @version.whodunnit
+          end
+        end
+      end
+    end
+
     context 'when a record is created' do
       setup do
         PaperTrail.whodunnit = 'Alice'
@@ -771,7 +831,7 @@ def without(&block)
       should 'store dynamic meta data based on a method of the item' do
         assert_equal @article.action_data_provider_method, @article.versions.last.action
       end
-      
+
       should 'store dynamic meta data based on an attribute of the item prior to creation' do
         assert_equal nil, @article.versions.last.title
       end
@@ -793,7 +853,7 @@ def without(&block)
         should 'store dynamic meta data which depends on the item' do
           assert_equal @article.id, @article.versions.last.article_id
         end
-        
+
         should 'store dynamic meta data based on an attribute of the item prior to the update' do
           assert_equal @initial_title, @article.versions.last.title
         end
@@ -814,7 +874,7 @@ def without(&block)
         should 'store dynamic meta data which depends on the item' do
           assert_equal @article.id, @article.versions.last.article_id
         end
-        
+
         should 'store dynamic meta data based on an attribute of the item prior to the destruction' do
           assert_equal @initial_title, @article.versions.last.title
         end