Web Development with Ruby on Rails, MyGOSSCON 2007

Web Development with Ruby on Rails MyGOSSCON 2007 Kamal Fariz Mahyuddin RSB

A full-stack framework for developing database-backed web applications according to the Model-View-Controller pattern.

A full-stack framework for developing database-backed web applications according to the Model-View-Controller A bunch of stuff that makes web developers happy! pattern. - David Heinemeier Hansson http://flickr.com/photos/pragdave/174964316/

2004 6 7 5

> 1 million downloads

Hundreds of plugins

~10k people on rubyonrails-talk

DB2 SybaseASA Informix Firebird MySQL SQLite Oracle PostgreSQL SQL Server

Ruby on Rails Model-View-Controller

MVC is like a bakery shop.

ActionController Model-View-Controller

ActiveRecord Model-View-Controller

ActionView Model-View-Controller

ActiveRecord Model-View-Controller

class Department < ActiveRecord::Base belongs_to :ministry has_many :officers has_many :projects end File: apps/models/department.rb

departments id name ministry_id 1 Jabatan Lanskap dan Taman 1 2 Jabatan Pembangunan Bandar 1 3 Jabatan Imigresen Malaysia 2

ministries id name 1 Kementerian Wilayah Persekutuan 2 Kementerian Hal Ehwal Dalam Negeri

dept = Department.find(1) => #<Department id: 1, name: 'Jabatan Lanskap dan Taman'> SELECT * FROM departments WHERE id = 1

dept.ministry => #<Ministry id: 1, name: 'Kementerian Wilayah Persekutuan'> SELECT * FROM ministries WHERE id = 1

class Ministry < ActiveRecord::Base has_many :departments end File: apps/models/ministry.rb

ministries id name 1 Kementerian Wilayah Persekutuan 2 Kementerian Hal Ehwal Dalam Negeri

departments id name ministry_id 1 Jabatan Lanskap dan Taman 1 2 Jabatan Pembangunan Bandar 1 3 Jabatan Imigresen Malaysia 2

ministry = Ministry.find(1) => #<Ministry id: 1, name: 'Kementerian Wilayah Persekutuan'> ministry.departments => [#<Department id: 1, name: 'Jabatan Lanskap dan Taman'>, #<Department id: 2, name: 'Jabatan Pembangunan Bandar'>] SELECT * FROM departments WHERE ministry_id = 1

Convention over Conﬁguration

ActiveRecord Conventions Model names are singular, e.g. Ministry. Table names are plural, e.g. ministries. Foreign-key columns are named model_id, e.g. ministry_id. Foreign key column goes onto the model that belongs_to another model, e.g. departments table has a column named ministry_id.

ActionController Model-View-Controller

http://mampu.gov.my/departments/show/1

http://mampu.gov.my/departments/show/1 http://mampu.gov.my/controller/action/id

/departments/show/1 /controller/action/id class DepartmentsController < ApplicationController def show @dept = Department.find(params[:id]) end end File: apps/controllers/departments_controller.rb

Remember this? Department.find(1)

/departments/show/1 /controller/action/id class DepartmentsController < ApplicationController def show @dept = Department.find(params[:id]) end end File: apps/controllers/departments_controller.rb

ActionController Conventions First segment of URL is the controller name, e.g. /departments/show/1, the controller is DepartmentsController. Second segment of URL is the controller action, e.g. /departments/show/1, the action is show in DepartmentsController. Third segment of URL is the ID, e.g. /departments/show/1, the value is accessible from params[:id].

ActionView Model-View-Controller

Remember this? class DepartmentsController < ApplicationController def show @dept = Department.find(params[:id]) end end

http://localhost/departments/show/1 Department: Jabatan Lanskap dan Taman Ministry: Kementerian Wilayah Persekutuan Projects: • Next Generation Network • e-Perolehan Integration

<html> <body> <h1>Department: <%= @dept.name %></h1> <h2>Ministry: <%= @dept.ministry.name %></h2> <h2>Projects</h2> <ul> <%= render :partial => @dept.projects %> </ul> </body> </html> File: apps/views/departments/show.html.erb

<li><%= project.title %></li> File: apps/views/projects/_project.html.erb

http://localhost/departments/show/1 Department: Jabatan Lanskap dan Taman Ministry: Kementerian Wilayah Persekutuan Projects: • Next Generation Network • e-Perolehan Integration

ActionView Conventions Instance variables set in controller action are automatically available in view, e.g. @dept in previous example. Values are displayed in view by enclosing it in <%= %>. Loops can be extracted into partials. Use Helpers as much as possible to code even less, e.g. link_to, form_for

Resources

Malaysia.rb Malaysia Ruby Brigade

~65 people in Google Groups ~28 people in Facebook Group

Meets every third Thursday of the month

Malaysia.rb 3rd Meetup July 2007

http://groups.google.com/group/malaysia-rb

Local Companies on Rails

RSB Freelance Developers

Local Ruby on Rails Sites

http://www.mampu.gov.my http://www.ravejoint.com http://www.geotude.com http://www.haze.net.my

Sneak Preview of Time Together

Your Department’s Next Internal Web Application

Web Development with Ruby on Rails, MyGOSSCON 2007

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