petrosp

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 here.

lelandbatey

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

millermedeiros

// Combine JS and CSS files
// ---
//
// Make sure you install the npm dependencies
//   > cd YOUR_PROJECT_FOLDER
//   > npm install
//
// Than run:
//   > node build

sergio-fry

;(function($){
  jQuery.fn.serializeJSON = function(){
    var aData = $(this).serializeArray();
    var result = {}
    for(key in aData){
      result[aData[key].name] = aData[key].value;
    }
    
    return result;
  }

jsierles

#!/usr/bin/env ruby
#
# Find bloating passengers and kill them gracefully. Run from cron every minute.
#

# required for passenger since cron has no environment
ENV['HTTPD'] = 'httpd'

MEM_LIMIT = ARGV[0] || 500