impressionist/README.md

![Impressionist Logo](https://github.com/charlotte-ruby/impressionist/raw/master/logo.png)

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 ;-)
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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
messages to impressions.  No reporting yet.. this thingy just creates the data.

What about bots?
----------------
They are ignored.  1200 known bots have been added to the ignore list as of Feb 1, 2011.  Impressionist uses this list:
http://www.user-agents.org/allagents.xml

Which versions of Rails and Ruby is this compatible with?
---------------------------------------------------------
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
------------
Add it to your Gemfile

    gem 'impressionist'

Install with Bundler

    bundle install

Generate the impressions table migration

    rails g impressionist

Run the migration

    rake db:migrate

The following fields are provided in the migration:

    t.string   "impressionable_type"  # model type: Widget
    t.integer  "impressionable_id"    # model instance ID: @widget.id
    t.integer  "user_id"              # automatically logs @current_user.id
    t.string   "controller_name"      # logs the controller name
    t.string   "action_name"          # logs the action_name
    t.string   "view_name"            # TODO: log individual views (as well as partials and nested partials)
    t.string   "request_hash"         # unique ID per request, in case you want to log multiple impressions and group them
    t.string   "session_hash"         # logs the rails session
    t.string   "ip_address"           # request.remote_ip
    t.string   "referrer"             # request.referer
    t.string   "message"              # custom message you can add
    t.datetime "created_at"           # I am not sure what this is.... Any clue?
    t.datetime "updated_at"           # never seen this one before either....  Your guess is as good as mine??

Usage
-----

1. Log all actions in a controller

        WidgetsController < ApplicationController
          impressionist
        end

2. Specify actions you want logged in a controller

        WidgetsController < ApplicationController
          impressionist :actions=>[:show,:index]
        end

3. Make your models impressionable.  This allows you to attach impressions to an AR model instance.  Impressionist will automatically log the Model name (based on action_name) and the id (based on params[:id]), but in order to get the count of impressions (example: @widget.impression_count), you will need to make your model impressionalble

        class Widget < ActiveRecord::Base
          is_impressionable
        end

4. Log an impression per model instance in your controller.  Note that it is not necessary to specify "impressionist" (usage #1) in the top of you controller if you are using this method.  If you add "impressionist" to the top of your controller and also use this method in your action, it will result in 2 impressions being logged (but associated with one request_hash)

        def show
          @widget = Widget.find
          impressionist(@widget,message:"wtf is a widget?") #message is optional
        end

5. Get unique impression count from a model.  This groups impressions by request_hash, so if you logged multiple impressions per request, it will only count them one time.  This unique impression count will not filter out unique users, only unique requests

        @widget.impressionist_count
        @widget.impressionist_count(:start_date=>"2011-01-01",:end_date=>"2011-01-05")
        @widget.impressionist_count(:start_date=>"2011-01-01")  #specify start date only, end date = now

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
-------------------
* Automatic impression logging in views.  For example, log initial view, and any partials called from initial view
* Customizable black list for user-agents or IP addresses.  Impressions will be ignored.  Web admin as part of the Engine.
* Reporting engine
* 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.
* 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.