Why I like Ruby on Rails: Part 1

Michel Grootjans — Tue, 02 Sep 2008 21:37:53 GMT

I'm starting to really enjoy what RoR offers out of the box. This framework is really designed around the application lifecycle we all try to reinvent on every project.

Rails

Rails is the framework for web development over a database. Compare it to asp.net on dotnet. However, Rails is much more than a web UI. Read on...

Ease of development

When creating any kind of object, extra files are being generated as well, like helper classes, test classes, database migration scripts, fixtures, ... Most of the quotes that follow are command line commands. Since I wanted to know exactly what's happening, I used only the command line, notepad++ and Firefox.

> rails my_test_project

Generates a complete project structure with MVC, database scripts, environment definitions, test repositories, configuration, ...

Management of multiple environments

With a freshly generated project, you get three environments: development, test and production. You can add as many as you like. Each environment has its own database, which can each be from a different vendor.

MVC

Rails supports the MVC pattern out of the box

> ruby script/generate controller Site index about help

This command generates:

A site_controller having index, about and help actions
A view for each of these actions
A site_helper class
A site_controller_test functional test

The three views are instantly up and running

> ruby script/generate model User

This command generates:

A user model. Equivalent to what we call an entity
A user_test unit test
A users test fixture. This is a file where you set up the users you want in the database when running tests
A database script for the new entity

Scaffolding is entirely supported:

> ruby script/generate scaffold Post blog_id:integer title:string body:text

> rake db:migrate

The first command will generate the MVC triad necessary to manage posts. The second will generate the database table to persist the actions.

Ever tried Ruby on Rails?

Michel Grootjans — Thu, 28 Aug 2008 22:51:29 GMT

I'm taking this step. This technology has been on my radar for quite a while. Now I'm taking the plunge.

I've bought this book that looks really promising on the subject. RailsSpace: Building a Social Networking Website with Ruby on Rails. I'm halfway chapter 6 right now, and I'M LOVING IT. I have decided to make the most out of this experience, so I'm going to build this application along with the book. I've set up my little SVN on Google where I will keep my evolution up to date.

Chapter 1: Introduction.

This one's easy. Just a narrative introduction.

Chapter 2: Getting started.

This chapter explains how to install Ruby, RubyGems and Rails. I also installed a mySql database since RoR seems to work well with it. It claims to be databse agnostic (shouldn't that be database polytheistic ?), so SqlServer shouldn't be a problem, but I don't want to go too far off the beaten path of the book.
All the major platforms are supported in the book, but the examples are Mac-based. I'm WinXP based, and up until now this hasn't bothered me a bit.

Then it moves to the actual creation of a project. This is the first step that made me feel all warm inside. Go to the console, navigate to whatever directory (to me that's d:\\projects) and type 'rails the_name_of_the_project_you_want'. That's it! You now have your whole project structure set up. Let me run you trough it quickly:

app
config
db
lib
log
public
script
test
tmp
vendor

Next I just start the web application by typing 'ruby script/server'. Bam, I've got a web site running on http://localhost:3000/ (don't click on this link... you might be disappointed). Of course this is not much, but it's a start.

Next I generate my first Controller with a few Views. I type 'ruby script/generate controller Site index about help'. This creates a controller named Site_controller and three views: index, about and help. That's it, we've basically built three web pages for our site. They're all using a master layout, similar to a master page in asp.net.

A nice highlight on what you can do in a view:

link_to "Home", :controller => :site, :action => :index

As a C# developer, the syntax looks a little alien to me, but I've had worse ;-) This inserts a link in a view that points to the action (==method) 'index' of the 'site_controller' class. You can exchange 'link_to' with 'link_to_unless_current' which will do exactly what it says.

Chapter 3: Modeling users

In RoR, models seem to be what we understand under Domain Objects in .net. Before I start modeling, I have to set up a database. TDD, BDD, DDD and other *DD aficionado's will probably be frowning right now, but bear with me. Magic's up ahead! In the config directory, theres a file called database.yml. This file holds the connection definition to all the databases I will be using during my development lifecycle: development, test, production. I just need to create two of these three databases: dev and test.

Next, I type 'ruby script/generate model User'. This generates a bunch of files. One particularly caught my attention: db/migrate/20080816134931_create_users.rb

After adding the fileds I need, the file looks like this:

class CreateUsers < ActiveRecord::Migration
def self.up
create_table :users do |t|

      t.column :screen_name, :string
      t.column :email,       :string
      t.column :password,    :string
    end
end

def self.down
drop_table :users
end
end

Do you see the magic? This file describes declaratively what needs to be done to the database to move to version 1 of the app. No SQL statements, just a declaration of the intent. At this time, the actual database is still empty. Let's change that: 'rake db:migrate'. The development database now contains the right table with the necessary records. 'rake db:migrate VERSION=0' will reverse the database to version 0. Further up on the road, you will be able to type 'rake db:migrate VERSION=0080816134931' to revert to the db version like it is now. Imagine the ease of deployment and rollback of deployments.

The road ahead

There's plenty of magic coming up. Chapter 3 isn't completely covered here. I'll be posting regular updates on this blog to keep you informed on my journey in this completely new world.