Merge pull request #12 from coryschires/master

Merged in the counter caching code. Added docs for previous pull request concerning recording unique impressions

.gitignore

@@ -1,5 +1,4 @@
 Gemfile.lock
-/test_app/db/migrate/20*
 /test_app/db/schema.rb
 /pkg
 *~

README.md

@@ -5,20 +5,14 @@ impressionist
 
 A lightweight plugin that logs impressions per action or manually per model
 
+I would not call this a stable plugin yet, although I have been running it in prod with no problems.  Use at your own risk ;-)
 ------------------------------------------------------------------------------------------------------------------------------
 
-NOTE: If you are upgrading from a version prior to 0.4.0, you will need to run this migration after the upgrade:
-
-https://github.com/charlotte-ruby/impressionist/blob/master/upgrade_migrations/version_0_4_0.rb
-
-If you don't run this migration you will receive this error: Unknown attribute : referrer
-
-
 What does this thing do?
 ------------------------
-Logs an impression... and I use that term loosely.  It can log page impressions (technically action impressions), but it is not limited to that.  
-You can log impressions multiple times per request.  And you can also attach it to a model.  The goal of this project is to provide customizable 
-stats that are immediately accessible in your application as opposed to using G Analytics and pulling data using their API.  You can attach custom 
+Logs an impression... and I use that term loosely.  It can log page impressions (technically action impressions), but it is not limited to that.
+You can log impressions multiple times per request.  And you can also attach it to a model.  The goal of this project is to provide customizable
+stats that are immediately accessible in your application as opposed to using G Analytics and pulling data using their API.  You can attach custom
 messages to impressions.  No reporting yet.. this thingy just creates the data.
 
 What about bots?
@@ -28,7 +22,7 @@ http://www.user-agents.org/allagents.xml
 
 Which versions of Rails and Ruby is this compatible with?
 ---------------------------------------------------------
-Rails 3.0.x and Ruby 1.9.2 (also tested on REE 1.8.7) - Sorry, but you need to upgrade if you are using Rails 2.  You know you want to anyways.. all the cool kids are doing it ;-)
+Rails 3.0.4 and Ruby 1.9.2 (also tested on REE 1.8.7) - Sorry, but you need to upgrade if you are using Rails 2.  You know you want to anyways.. all the cool kids are doing it ;-)
 
 Installation
 ------------
@@ -101,17 +95,49 @@ Usage
 6. Get the unique impression count from a model filtered by IP address.  This in turn will give you impressions with unique request_hash, since rows with the same request_hash will have the same IP address.
 
         @widget.impressionist_count(:filter=>:ip_address)
-        
+
 7. Get the unique impression count from a model filtered by session hash.  Same as #6 regarding request hash.  This may be more desirable than filtering by IP address depending on your situation, since filtering by IP may ignore visitors that use the same IP.  The downside to this filtering is that a user could clear session data in their browser and skew the results.
 
         @widget.impressionist_count(:filter=>:session_hash)
-    
+
 8. Get total impression count.  This may return more than 1 impression per http request, depending on how you are logging impressions
 
         @widget.impressionist_count(:filter=>:all)
 
 Logging impressions for authenticated users happens automatically.  If you have a current_user helper or use @current_user in your before_filter to set your authenticated user, current_user.id will be written to the user_id field in the impressions table.
 
+Adding a counter cache
+----------------------
+Impressionist makes it easy to add a `counter_cache` column to your model. The most basic configuration looks like:
+
+  is_impressionable :counter_cache => true
+
+This will automatically increment the `impressions_count` column in the included model. Note: You'll need to add that column to your model. If you'd like specific a different column name, you can:
+
+  is_impressionable :counter_cache => { :column_name => :my_column }
+
+If you'd like to include only unique impressions in your count:
+
+  is_impressionable :counter_cache => { :column_name => :my_column, :unique => true }
+
+
+What if I only want to record unique impressions?
+-------------------------------------------------
+Maybe you only care about unique impressions and would like to eliminate unnecessary database calls. You can specify conditions for recording impressions in your controller:
+
+  # only record impression if the request has a unique combination of type, id, and session
+  impressionist :unique => [:impressionable_type, :impressionable_id, :session_hash]
+
+  # only record impression if the request has a unique combination of controller, action, and session
+  impressionist :unique => [:controller_name, :action_name, :session_hash]
+
+  # only record impression if session is unique
+  impressionist :unique => [:session_hash]
+
+Or you can use the `impressionist` method directly:
+
+  impressionist(impressionable, "some message", :unique => [:session_hash])
+
 
 Development Roadmap
 -------------------
@@ -121,14 +147,14 @@ Development Roadmap
 * AB testing integration
 
 Contributing to impressionist
------------------------------ 
+-----------------------------
 * Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
 * Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
 * Fork the project
 * Start a feature/bugfix branch
 * Commit and push until you are happy with your contribution
 * Make sure to add rpsec tests for it. Patches or features without tests will be ignored.  Also, try to write better tests than I do ;-)
-* If adding engine controller or view functionality, use HAML and Inherited Resources.  
+* If adding engine controller or view functionality, use HAML and Inherited Resources.
 * All testing is done inside a small Rails app (test_app).  You will find specs within this app.
 
 Copyright (c) 2011 John McAliley. See LICENSE.txt for further details.

app/models/impression.rb

@@ -1,3 +1,16 @@
 class Impression < ActiveRecord::Base
   belongs_to :impressionable, :polymorphic=>true
+
+  after_save :update_impressions_counter_cache
+
+  private
+
+  def update_impressions_counter_cache
+    impressionable_class = self.impressionable_type.constantize
+
+    if impressionable_class.counter_cache_options
+      resouce = impressionable_class.find(self.impressionable_id)
+      resouce.try(:update_counter_cache)
+    end
+  end
 end

app/models/impressionist/impressionable.rb

@@ -1,15 +1,38 @@
 module Impressionist
   module Impressionable
-    def is_impressionable
-      has_many :impressions, :as=>:impressionable
-      include InstanceMethods
+
+    def self.included(base)
+      base.extend ClassMethods
+      base.send(:include, InstanceMethods)
     end
-    
+
+    module ClassMethods
+      attr_accessor :cache_options
+      @cache_options = nil
+
+      def is_impressionable(options={})
+        has_many :impressions, :as=>:impressionable
+        @cache_options = options[:counter_cache]
+      end
+
+      def counter_cache_options
+        if @cache_options
+          options = { :column_name => :impressions_count, :unique => false }
+          options.merge!(@cache_options) if @cache_options.is_a?(Hash)
+          options
+        end
+      end
+
+      def counter_caching?
+        counter_cache_options.present?
+      end
+    end
+
     module InstanceMethods
       def impressionable?
         true
       end
-      
+
       def impressionist_count(options={})
         options.reverse_merge!(:filter=>:request_hash, :start_date=>nil, :end_date=>Time.now)
         imps = options[:start_date].blank? ? impressions : impressions.where("created_at>=? and created_at<=?",options[:start_date],options[:end_date])
@@ -18,7 +41,14 @@ module Impressionist
         end
         imps.all.size
       end
-      
+
+      def update_counter_cache
+        cache_options = self.class.counter_cache_options
+        column_name = cache_options[:column_name].to_sym
+        count = cache_options[:unique] ? impressionist_count(:filter => :ip_address) : impressionist_count
+        update_attribute(column_name, count)
+      end
+
       # OLD METHODS - DEPRECATE IN V0.5
       def impression_count(start_date=nil,end_date=Time.now)
         impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=>:all})
@@ -27,14 +57,15 @@ module Impressionist
       def unique_impression_count(start_date=nil,end_date=Time.now)
         impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :request_hash})
       end
-      
+
       def unique_impression_count_ip(start_date=nil,end_date=Time.now)
         impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :ip_address})
       end
-      
+
       def unique_impression_count_session(start_date=nil,end_date=Time.now)
         impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :session_hash})
       end
     end
+
   end
 end

lib/impressionist/engine.rb

@@ -2,11 +2,11 @@ require "impressionist"
 require "rails"
 
 module Impressionist
-  class Engine < Rails::Engine    
+  class Engine < Rails::Engine
     initializer 'impressionist.extend_ar' do |app|
-      ActiveRecord::Base.extend Impressionist::Impressionable
+      ActiveRecord::Base.send(:include, Impressionist::Impressionable)
     end
-    
+
     initializer 'impressionist.controller' do
       ActiveSupport.on_load(:action_controller) do
         include ImpressionistController::InstanceMethods

test_app/Gemfile.lock

@@ -1,5 +1,5 @@
 PATH
-  remote: /home/mio/prog/projects/impressionist
+  remote: /Users/coryschires/Desktop/impressionist
   specs:
     impressionist (0.4.0)
 
@@ -45,7 +45,7 @@ GEM
     autotest-standalone (4.5.8)
     bcrypt-ruby (3.0.1)
     builder (3.0.0)
-    capybara (1.1.1)
+    capybara (1.1.2)
       mime-types (>= 1.16)
       nokogiri (>= 1.3.3)
       rack (>= 1.0.0)
@@ -54,10 +54,10 @@ GEM
       xpath (~> 0.1.4)
     childprocess (0.2.2)
       ffi (~> 1.0.6)
-    cucumber (1.1.1)
+    cucumber (1.1.3)
       builder (>= 2.1.2)
       diff-lcs (>= 1.1.2)
-      gherkin (~> 2.6.0)
+      gherkin (~> 2.6.7)
       json (>= 1.4.6)
       term-ansicolor (>= 1.0.6)
     cucumber-rails (1.2.0)
@@ -65,12 +65,12 @@ GEM
       cucumber (>= 1.1.1)
       nokogiri (>= 1.5.0)
     daemons (1.0.10)
-    database_cleaner (0.6.7)
+    database_cleaner (0.7.0)
     diff-lcs (1.1.3)
     erubis (2.7.0)
-    ffi (1.0.9)
+    ffi (1.0.11)
     gem_plugin (0.2.3)
-    gherkin (2.6.2)
+    gherkin (2.6.8)
       json (>= 1.4.6)
     hike (1.2.1)
     i18n (0.6.0)
@@ -129,10 +129,10 @@ GEM
       activesupport (~> 3.0)
       railties (~> 3.0)
       rspec (~> 2.7.0)
-    rubyzip (0.9.4)
-    selenium-webdriver (2.10.0)
+    rubyzip (0.9.5)
+    selenium-webdriver (2.13.0)
       childprocess (>= 0.2.1)
-      ffi (= 1.0.9)
+      ffi (~> 1.0.9)
       json_pure
       rubyzip
     spork (0.8.5)

test_app/app/controllers/dummy_controller.rb

@@ -2,5 +2,5 @@
 class DummyController < ActionController::Base
 
   impressionist
-  
+
 end

test_app/app/models/dummy.rb

@@ -0,0 +1,7 @@
+# We don't really care about this model. It's just being used to test the uniqueness controller
+# specs. Nevertheless, we need a model because the counter caching functionality expects it.
+#
+class Dummy < ActiveRecord::Base
+  self.abstract_class = true # doesn't need to be backed by an actual table
+  is_impressionable
+end

test_app/app/models/widget.rb

@@ -0,0 +1,3 @@
+class Widget < ActiveRecord::Base
+  is_impressionable :counter_cache => true
+end

test_app/db/migrate/20111127184039_create_widgets.rb

@@ -0,0 +1,15 @@
+class CreateWidgets < ActiveRecord::Migration
+  def self.up
+    create_table :widgets do |t|
+      t.string :name
+      t.integer :impressions_count
+
+      t.timestamps
+    end
+  end
+
+  def self.down
+    drop_table :widgets
+  end
+end
+

test_app/db/migrate/20111127193841_create_impressions_table.rb

@@ -0,0 +1,37 @@
+class CreateImpressionsTable < ActiveRecord::Migration
+  def self.up
+    create_table :impressions, :force => true do |t|
+      t.string :impressionable_type
+      t.integer :impressionable_id
+      t.integer :user_id
+      t.string :controller_name
+      t.string :action_name
+      t.string :view_name
+      t.string :request_hash
+      t.string :session_hash
+      t.string :ip_address
+      t.string :message
+      t.string :referrer
+      t.timestamps
+    end
+    add_index :impressions, [:impressionable_type, :impressionable_id, :request_hash], :name => "poly_request_index", :unique => false
+    add_index :impressions, [:impressionable_type, :impressionable_id, :ip_address], :name => "poly_ip_index", :unique => false
+    add_index :impressions, [:impressionable_type, :impressionable_id, :session_hash], :name => "poly_session_index", :unique => false    
+    add_index :impressions, [:controller_name,:action_name,:request_hash], :name => "controlleraction_request_index", :unique => false
+    add_index :impressions, [:controller_name,:action_name,:ip_address], :name => "controlleraction_ip_index", :unique => false
+    add_index :impressions, [:controller_name,:action_name,:session_hash], :name => "controlleraction_session_index", :unique => false        
+    add_index :impressions, :user_id
+  end
+
+  def self.down
+    remove_index :impressions, :name => :poly_request_index
+    remove_index :impressions, :name => :poly_ip_index
+    remove_index :impressions, :name => :poly_session_index        
+    remove_index :impressions, :name => :controlleraction_request_index
+    remove_index :impressions, :name => :controlleraction_ip_index
+    remove_index :impressions, :name => :controlleraction_session_index        
+    remove_index :impressions, :user_id
+    
+    drop_table :impressions
+  end
+end

test_app/spec/controllers/controller_spec.rb

@@ -1,14 +1,14 @@
 require 'spec_helper.rb'
 
 describe ArticlesController do
-  fixtures :articles,:impressions,:posts
+  fixtures :articles,:impressions,:posts,:widgets
   render_views
-  
+
   it "should make the impressionable_hash available" do
     get "index"
     response.body.include?("false").should eq true
   end
-  
+
   it "should log an impression with a message" do
     get "index"
     Impression.all.size.should eq 12
@@ -16,7 +16,7 @@ describe ArticlesController do
     Article.first.impressions.last.controller_name.should eq "articles"
     Article.first.impressions.last.action_name.should eq "index"
   end
-  
+
   it "should log an impression without a message" do
     get "show", :id=> 1
     Impression.all.size.should eq 12
@@ -24,18 +24,18 @@ describe ArticlesController do
     Article.first.impressions.last.controller_name.should eq "articles"
     Article.first.impressions.last.action_name.should eq "show"
   end
-  
+
   it "should log the user_id if user is authenticated (@current_user before_filter method)" do
     session[:user_id] = 123
     get "show", :id=> 1
     Article.first.impressions.last.user_id.should eq 123
   end
-  
+
   it "should not log the user_id if user is authenticated" do
     get "show", :id=> 1
     Article.first.impressions.last.user_id.should eq nil
   end
-  
+
   it "should log the request_hash, ip_address, referrer and session_hash" do
     get "show", :id=> 1
     Impression.last.request_hash.size.should eq 64
@@ -43,13 +43,13 @@ describe ArticlesController do
     Impression.last.session_hash.size.should eq 32
     Impression.last.referrer.should eq nil
   end
-  
+
   it "should log the referrer when you click a link" do
     visit article_url(Article.first)
     click_link "Same Page"
     Impression.last.referrer.should eq "http://test.host/articles/1"
   end
-end  
+end
 
 describe PostsController do
   it "should log impression at the action level" do
@@ -60,7 +60,7 @@ describe PostsController do
     Impression.last.impressionable_type.should eq "Post"
     Impression.last.impressionable_id.should eq 1
   end
-  
+
   it "should log the user_id if user is authenticated (current_user helper method)" do
     session[:user_id] = 123
     get "show", :id=> 1
@@ -69,6 +69,12 @@ describe PostsController do
 end
 
 describe WidgetsController do
+
+  before(:each) do
+    @widget = Widget.find(1)
+    Widget.stub(:find).and_return(@widget)
+  end
+
   it "should log impression at the per action level" do
     get "show", :id=> 1
     Impression.all.size.should eq 12
@@ -77,17 +83,17 @@ describe WidgetsController do
     get "new"
     Impression.all.size.should eq 13
   end
-  
+
   it "should not log impression when user-agent is in wildcard list" do
     request.stub!(:user_agent).and_return('somebot')
     get "show", :id=> 1
     Impression.all.size.should eq 11
   end
-  
+
   it "should not log impression when user-agent is in the bot list" do
     request.stub!(:user_agent).and_return('Acoon Robot v1.50.001')
     get "show", :id=> 1
-    Impression.all.size.should eq 11    
+    Impression.all.size.should eq 11
   end
   
   describe "impressionist unique options" do
@@ -117,4 +123,3 @@ describe WidgetsController do
   end
   
 end
-  

test_app/spec/controllers/impressionist_uniqueness_spec.rb

@@ -2,19 +2,19 @@ require "spec_helper.rb"
 
 # we use the posts controller as it uses the impressionsist module. any such controller would do.
 describe DummyController do
-  
+
   before do
-      @impression_count = Impression.all.size
-    end
-  
-  describe "impressionist filter uniqueness" do  
-  
+    @impression_count = Impression.all.size
+  end
+
+  describe "impressionist filter uniqueness" do
+
     it "should ignore uniqueness if not requested" do
       controller.impressionist_subapp_filter(nil, nil)
       controller.impressionist_subapp_filter(nil, nil)
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize unique session" do
       # the following line was necessary as session hash returned a binary string (ASCII-8BIT encoded)
       controller.stub!(:session_hash).and_return(request.session_options[:id].encode("ISO-8859-1"))
@@ -22,58 +22,58 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:session_hash])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique ip" do
       controller.request.stub!(:remote_ip).and_return("1.2.3.4")
       controller.impressionist_subapp_filter(nil, [:ip_address])
       controller.impressionist_subapp_filter(nil, [:ip_address])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique request" do
       controller.impressionist_subapp_filter(nil, [:request_hash])
       controller.impressionist_subapp_filter(nil, [:request_hash])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique action" do
       controller.stub!(:action_name).and_return("test_action")
       controller.impressionist_subapp_filter(nil, [:action_name])
       controller.impressionist_subapp_filter(nil, [:action_name])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique controller" do
-      controller.stub!(:controller_name).and_return("test_controller")
+      controller.stub!(:controller_name).and_return("post")
       controller.impressionist_subapp_filter(nil, [:controller_name])
       controller.impressionist_subapp_filter(nil, [:controller_name])
       Impression.should have(@impression_count + 1).records
     end
-    
-     it "should recognize unique user" do
+
+    it "should recognize unique user" do
       controller.stub!(:user_id).and_return(42)
       controller.impressionist_subapp_filter(nil, [:user_id])
       controller.impressionist_subapp_filter(nil, [:user_id])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique referer" do
       controller.request.stub!(:referer).and_return("http://foo/bar")
       controller.impressionist_subapp_filter(nil, [:referrer])
       controller.impressionist_subapp_filter(nil, [:referrer])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique id" do
       controller.stub!(:params).and_return({:id => "666"}) # for correct impressionable id in filter
       controller.impressionist_subapp_filter(nil, [:impressionable_id])
       controller.impressionist_subapp_filter(nil, [:impressionable_id])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     # extra redundant test for important controller and action combination.
     it "should recognize different controller and action" do
-      controller.stub!(:controller_name).and_return("test_controller")
+      controller.stub!(:controller_name).and_return("post")
       controller.stub!(:action_name).and_return("test_action")
       controller.impressionist_subapp_filter(nil, [:controller_name, :action_name])
       controller.impressionist_subapp_filter(nil, [:controller_name, :action_name])
@@ -82,12 +82,12 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:controller_name, :action_name])
       controller.impressionist_subapp_filter(nil, [:controller_name, :action_name])
       Impression.should have(@impression_count + 2).records
-      controller.stub!(:controller_name).and_return("another_controller")
+      controller.stub!(:controller_name).and_return("article")
       controller.impressionist_subapp_filter(nil, [:controller_name, :action_name])
       controller.impressionist_subapp_filter(nil, [:controller_name, :action_name])
       Impression.should have(@impression_count + 3).records
     end
-    
+
     it "should recognize different action" do
       controller.stub!(:action_name).and_return("test_action")
       controller.impressionist_subapp_filter(nil, [:action_name])
@@ -98,18 +98,18 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:action_name])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize different controller" do
-      controller.stub!(:controller_name).and_return("test_controller")
+      controller.stub!(:controller_name).and_return("post")
       controller.impressionist_subapp_filter(nil, [:controller_name])
       controller.impressionist_subapp_filter(nil, [:controller_name])
       Impression.should have(@impression_count + 1).records
-      controller.stub!(:controller_name).and_return("another_controller")
+      controller.stub!(:controller_name).and_return("article")
       controller.impressionist_subapp_filter(nil, [:controller_name])
       controller.impressionist_subapp_filter(nil, [:controller_name])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize different session" do
       controller.stub!(:session_hash).and_return("foo")
       controller.impressionist_subapp_filter(nil, [:session_hash])
@@ -120,7 +120,7 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:session_hash])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize different ip" do
       controller.request.stub!(:remote_ip).and_return("1.2.3.4")
       controller.impressionist_subapp_filter(nil, [:ip_address])
@@ -131,7 +131,7 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:ip_address])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize different referer" do
       controller.request.stub!(:referer).and_return("http://foo/bar")
       controller.impressionist_subapp_filter(nil, [:referrer])
@@ -142,7 +142,7 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:referrer])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize different id" do
       controller.stub!(:params).and_return({:id => "666"}) # for correct impressionable id in filter
       controller.impressionist_subapp_filter(nil, [:impressionable_type, :impressionable_id])
@@ -152,7 +152,7 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:impressionable_type, :impressionable_id])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize combined uniqueness" do
       controller.stub!(:action_name).and_return("test_action")
       controller.impressionist_subapp_filter(nil, [:ip_address, :request_hash, :action_name])
@@ -165,7 +165,7 @@ describe DummyController do
       controller.impressionist_subapp_filter(nil, [:request_hash])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize combined non-uniqueness" do
       controller.stub!(:action_name).and_return(nil)
       controller.impressionist_subapp_filter(nil, [:ip_address, :action_name])
@@ -174,21 +174,21 @@ describe DummyController do
       controller.stub!(:action_name).and_return("another_action")
       controller.impressionist_subapp_filter(nil, [:ip_address, :action_name])
       Impression.should have(@impression_count + 3).records
-    end     
-    
+    end
+
   end
-  
-  describe "impressionist method uniqueness for impressionables" do  
-    
+
+  describe "impressionist method uniqueness for impressionables" do
+
     # in this test we reuse the post model. might break if model changes.
-    
+
     it "should ignore uniqueness if not requested" do
       impressionable = Post.create
       controller.impressionist impressionable
       controller.impressionist impressionable
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize unique session" do
       # the following line was necessary as session hash returned a binary string (ASCII-8BIT encoded)
       controller.stub!(:session_hash).and_return(request.session_options[:id].encode("ISO-8859-1"))
@@ -197,7 +197,7 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:session_hash])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique ip" do
       controller.request.stub!(:remote_ip).and_return("1.2.3.4")
       impressionable = Post.create
@@ -205,22 +205,22 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:ip_address])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique request" do
       impressionable = Post.create
       controller.impressionist(impressionable, nil, :unique => [:request_hash])
       controller.impressionist(impressionable, nil, :unique => [:request_hash])
       Impression.should have(@impression_count + 1).records
     end
-    
-     it "should recognize unique user" do
+
+    it "should recognize unique user" do
       controller.stub!(:user_id).and_return(666)
       impressionable = Post.create
       controller.impressionist(impressionable, nil, :unique => [:user_id])
       controller.impressionist(impressionable, nil, :unique => [:user_id])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize unique referer" do
       controller.request.stub!(:referer).and_return("http://foo/bar")
       impressionable = Post.create
@@ -228,7 +228,7 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:referrer])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize different session" do
       impressionable = Post.create
       controller.stub!(:session_hash).and_return("foo")
@@ -240,7 +240,7 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:session_hash])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize different ip" do
       controller.request.stub!(:remote_ip).and_return("1.2.3.4")
       impressionable = Post.create
@@ -252,7 +252,7 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:ip_address])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize different user" do
       impressionable = Post.create
       controller.stub!(:user_id).and_return(666)
@@ -264,7 +264,7 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:user_id])
       Impression.should have(@impression_count + 2).records
     end
-    
+
     it "should recognize combined uniqueness" do
       impressionable = Post.create
       controller.stub!(:session_hash).and_return("foo")
@@ -278,7 +278,7 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:request_hash])
       Impression.should have(@impression_count + 1).records
     end
-    
+
     it "should recognize combined non-uniqueness" do
       impressionable = Post.create
       controller.stub!(:session_hash).and_return(nil)
@@ -289,11 +289,11 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:ip_address, :session_hash])
       Impression.should have(@impression_count + 3).records
     end
-    
+
   end
-  
+
   describe "impressionist filter and method uniqueness" do
-  
+
     it "should recognize uniqueness" do
       impressionable = Post.create
       controller.stub!(:controller_name).and_return("posts") # for correct impressionable type in filter
@@ -305,8 +305,8 @@ describe DummyController do
       controller.impressionist(impressionable, nil, :unique => [:ip_address, :request_hash, :session_hash])
       Impression.should have(@impression_count + 1).records
     end
-    
+
   end
-  
+
 end
 

test_app/spec/fixtures/widgets.yml

@@ -0,0 +1,4 @@
+one:
+  id: 1
+  name: A Widget
+  impressions_count: 0

test_app/spec/models/counter_caching_spec.rb

@@ -0,0 +1,30 @@
+require 'spec_helper'
+
+describe Impression do
+  fixtures :widgets
+
+  before(:each) do
+    @widget = Widget.find(1)
+    Impression.destroy_all
+  end
+
+  describe "self#counter_caching?" do
+    it "should know when counter caching is enabled" do
+      Widget.should be_counter_caching
+    end
+
+    it "should know when counter caching is disabled" do
+      Article.should_not be_counter_caching
+    end
+  end
+
+  describe "#update_counter_cache" do
+    it "should update the counter cache column to reflect the correct number of impressions" do
+      lambda {
+         Impression.create(:impressionable_type => @widget.class.name, :impressionable_id => @widget.id)
+         @widget.reload
+       }.should change(@widget, :impressions_count).from(0).to(1)
+    end
+  end
+
+end

test_app/spec/models/model_spec.rb

@@ -49,6 +49,8 @@ describe Impression do
     @article.impressionist_count(:filter=>:session_hash).should eq 7
   end
   
+  
+  
   #OLD COUNT METHODS.  DEPRECATE SOON
   it "should return the impression count with no date range specified" do
     @article.impression_count.should eq 11