khoan

# So I was trying to use named route helpers in sprockets, and the app was hosted in a subdirectory.
# This is what I came up with. Please share your hackeries.
#
# using named routes in sprocket Rails 3.1
# you can use this in app/assets/javascripts/bam.js.erb
# or any other erb sprocket asset

Rails.application.routes.url_helpers.bam_path(
  :script_name => ApplicationController.config.relative_url_root
)

khoan

# Our User model with default_scope of active users,
# and a :vip scope
#
class User
  include Mongoid::Document

  field :status

  # now only active users can be authenticated
  default_scope where(status: 'active')

khoan

# lib/vip_authenticatable.rb
#
# We introduce :vip_authenticatable strategy to Warden.
# With this strategy your login form might look something like
#
# <form action="/path/to/create/session">
#   <input name="vip[:id]" placeholder="Enter your VIP No.">
#   <input type="submit">
# </form>
#

khoan

# config/initializers/devise.rb
#
# We now ask Warden to use :vip_authenticatable when authenticating.
#
# Also, we instruct Warden to load User from session without any default scoping.
#
Devise.setup do |config|
  config.warden do |manager|
    require Rails.root+'lib/vip_authenticable'
    manager.default_strategies(scope: :user).unshift :vip_authenticatable

khoan

Caveat: I have not read James Coplien book about DCI.

But to put simply: Data Context Interaction (Roles) is a technique to capture the run-time behavior of your system. I'll leave the benefits to your imagination, and gleaning from further reading of numerous sources about the subject.

How do we apply DCI to Rails? Here's one proposed folder structure:

app/contexts/
app/roles/
app/models/

khoan

Run this on ruby 1.9

require 'delegate'

class Bam < SimpleDelegator
  def bam
    defined? Bam
  end

khoan

# ruby 1.9.3-p125-perf
# Rails 3.2.0

# app/bam/ham.rb
module Bam
  class Ham
  end
end

# on rails console

khoan

class SimulateTraffic
  def initialize
    @dates = (first_date_of_last_month..Date.today).to_a
    @types = [:pageviews, :subscriptions, :shares, :clicks]
  end 

  def first_date_of_last_month
    prev_month = Date.today.prev_month

    Date.new(prev_month.year, prev_month.month, 1)

khoan

$ cat ~/Library/LaunchAgents/org.memcached.plist 
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <dict>
    <key>Label</key>
    <string>org.memcached</string>
    <key>KeepAlive</key>
    <true/>
    <key>ProgramArguments</key>

khoan

#!/bin/sh
#
# usage: heroku_pg_pull [appname] [local database name]
#
function heroku_pg_pull(){
  echo "!   WARNING: Data in the local database '$2' will be destroyed."
  echo "    Type '$2' to overwrite data in local database '$2'"
  read -p "> " local_database_name
  echo
  if [ "$local_database_name" == "$2" ]; then