israelb

Building Rich Domain Models in Rails.

Part 1. Decoupling Persistence.

Abstract

Domain model is an effective tool for software development. It can be used to express really complex business logic, and to verify and validate the understanding of the domain among stakeholders. Building rich domain models in Rails is hard. Primarily, because of Active Record, which doesn't play well with the domain model approach.

One way to deal with this problem is to use an ORM implementing the data mapper pattern. Unfortunately, there is no production ready ORM doing that for Ruby. DataMapper 2 is going to be the first one.

Another way is to use Active Record just as a persistence mechanism and build a rich domain model on top of it. That's what I'm going to talk about in this article.

israelb

Deploy your site with git

This gist assumes:

• you have a local git repo
• with an online remote repository (github / bitbucket etc)
• and a cloud server (Rackspace cloud / Amazon EC2 etc)
  • your (PHP) scripts are served from /var/www/html/
  • your webpages are executed by apache
• apache's home directory is /var/www/

israelb

# lib/tasks/db.rake
namespace :db do

  desc "Dumps the database to db/APP_NAME.dump"
  task :dump => :environment do
    cmd = nil
    with_config do |app, host, db, user|
      cmd = "pg_dump --host #{host} --username #{user} --verbose --clean --no-owner --no-acl --format=c #{db} > #{Rails.root}/db/#{app}.dump"
    end
    puts cmd

israelb

class AccountsController < ApplicationController
  def update
    @account = Account.find(params[:id])

    respond_to do |format|
      if @account.update_attributes(account_params)
        format.html { redirect_to @account, notice: 'Account was successfully updated.' }
      else
        format.html { render action: "edit" }
      end

israelb

PSQL

Magic words:

psql -U postgres

If run with -E flag, it will describe the underlaying queries of the \ commands (cool for learning!).

Most \d commands support additional param of __schema__.name__ and accept wildcards like *.*

israelb

package main

import (
  "fmt"
  "time"
)

type guestConnection struct {
  ip       string
  userName string

israelb

// chat/httpservice/main.go

package httpService

import (
  "fmt"
  "time"
)

func SendNotification() {

israelb

#Documentación GoLang Español

Detalles

• Escribo todo al mismo tiempo que nos capacitan para poder reflejar y expresar bien lo que nos dicen los chicos de GrupoEsfera.
• Me inspiré mucho con los ejemplos y dichos de GoTour, pero traté de complementarlos con el conocimiento de Diego.
• Separé Variables, Punteros, Estructuras, Slices y Mapas porque me parecen conceptos deberían tener sus propias secciones para no confundir(me).
• Si me confundo Pointer Receiver y Pointer Retriever, no es mi culpa.

israelb

AWS Remote Git Setup

Get a local git repo up on an EC2 Instance.

Add youself to SSH Authentication:

Add yourself to the ssh auth agent, if you haven't already.

ssh-add path/to/your/EC2.pem

Set up destination directory:

israelb

package main

import (
	"fmt"
	"labix.org/v2/mgo"
	"labix.org/v2/mgo/bson"
	"time"
)

type Person struct {