Putting together a traffic analytics model and controller for a Ruby on Rails app based on this presentation about Scribd http://www.scribd.com/doc/49575/Scaling-Rails-Presentation-From-Scribd-Launch (see slides 17 to 22).

application_controller.rb

class ApplicationController < ActionController::Base
  helper :all # include all helpers, all the time
  protect_from_forgery # See ActionController::RequestForgeryProtection for details

  # Scrub sensitive parameters from your log
  # filter_parameter_logging :password
  
  before_filter :log_page_view, :except => [:destroy]
  
  private
  
  def log_page_view
    PageView.log_page_view(request,session)
  end
end

create_page_views.rb

class CreatePageViews < ActiveRecord::Migration
  def self.up
    create_table :page_views do |t|
      t.column "user_id", :integer
      t.column "request_url", :string, :limit => 200
      t.column "session", :string, :limit => 32
      t.column "ip_address", :string, :limit => 16
      t.column "referer", :string, :limit => 200
      t.column "user_agent", :string, :limit => 200
      t.column "created_at", :timestamp
    end
  end

  def self.down
    drop_table :page_views
  end
end

page_view.rb

class PageView < ActiveRecord::Base
  validates_presence_of :ip_address
  validates_presence_of :user_agent
  
  # just so you know...
  # you'd do this with SQL directly, rather than using AR models
  # but for a couple hundred page views, this will be OK

  def self.log_page_view(request,session)
    pageview = PageView.new

    pageview.user_id = session[:user_id] || "0"
    pageview.request_url = request.url
    pageview.session = session[:session_id] || "unknown"
    pageview.ip_address = request.remote_ip
    pageview.referer = request.referer
    pageview.user_agent = request.headers["User-Agent"]
    pageview.save
  end
end

page_views_controller.rb

class PageViewsController < ApplicationController
  layout 'layout'

  def index
    @pageviews = PageView.find(:all)
    respond_to do |format|
      format.html # index.html.erb
    end
  end

  # DELETE /posts/1
  # DELETE /posts/1.xml
  def destroy
    @pageview = PageView.find(params[:id])
    @pageview.destroy

    respond_to do |format|
      format.html { redirect_to(page_views_url) }
    end
  end
end