rails

var DateHelper = {
  // Takes the format of "Jan 15, 2007 15:45:00 GMT" and converts it to a relative time
  // Ruby strftime: %b %d, %Y %H:%M:%S GMT
  time_ago_in_words_with_parsing: function(from) {
    var date = new Date; 
    date.setTime(Date.parse(from));
    return this.time_ago_in_words(date);
  },
  
  time_ago_in_words: function(from) {

rails

products = Product.where("price = 100").limit(5) # No query executed yet
products = products.order("created_at DESC")     # Adding to the query, still no execution
products.each { |product| puts product.price }   # That's when the SQL query is actually fired

class Product < ActiveRecord::Base
  named_scope :pricey, where("price > 100")
  named_scope :latest, order("created_at DESC").limit(10)
end

rails

class SessionsController < ApplicationController
  skip_before_filter :authorize, :only => [ :new, :create ]
  
  def new
  end
  
  def create
    if user = User.authenticate(params[:name], params[:password])
      session[:user_id] = user.id
      redirect_to admin_products_url