Web application frameworks (WAFs) provide a standard structure for building dynamic websites and web applications using the model-view-controller (MVC) pattern. A typical WAF includes features like asset management, security helpers, scaffolding tools, internationalization support, templating engines, routing and URL mapping, database access abstraction, and caching. Popular WAFs include Ruby on Rails, Django, Laravel, and Spring. WAFs handle common tasks like routing requests to controllers and fetching data from models to display in views.

1. Web Application Frameworks
(WAF)
Ako Kaman
@scheperson

2. What is a WAF?
• A general purpose software framework
• Used to build:
• Dynamic websites
• Web applications
• Web API
• Mostly based on MVC pattern
• Push based (more popular)
• Pull based

3. Why should I bother using a WAF?
• Community support
• Don’t reinvent the wheel
• Better application structure
• Decrease development time
• Free tools and components (more on this later)
• Hundreds of developers are smarter than your team! (RoR => 3477)

4. What is included in a typical WAF?
• Asset management (some WAFs)
• Generating sprites
• Pre-compiling assets for production
• Compiling SASS, Less and Coffescript on the fly (development)
• Helpers
• Security
• Local authentication
• Using OAuth
• Controllers
• Test tools

5. What is included in a typical WAF? (cont.)
• Scaffolding
• Command line tools
• I18n and L10n support
• Templating engine (View layer)
• Routing and URL mapping (no Default.aspx)!
• Database access and abstraction (Model layer)
• Migrations
• Caching data
• Databased agnostic
• Object oriented database access (ORM)

6. How does MVC work?
Router
Controller Model
Browser
View
Request
Dispatch
Fetch dataPush data
Render Response

7. Some WAFs out there
• PHP
• Yii
• Laravel
• FuelPHP
• CakePHP
• Zend Framework
• CodeIgniter (dead) => ExpressionEngine
• Symfony => Yahoo Bookmarks, Delicious, DailyMotion
• Python
• Flask
• Pylons
• Django => Pinterest, Disqus, Instagram, Mozilla, Rdio

8. Some WAFs out there (cont.)
• Java/Scala
• Lift => FourSquare
• Play => LinkedIn, Klout, The Guardian
• Java
• Grails
• Spring
• ASP.NET (C#, VB) :(
• ASP.NET MVC
• Ruby :)
• Sinatra => Apple, BBC, Heroku
• Ruby on Rails =>Twitter, GitHub, Basecamp, Groupon, SoundCloud

10. How does MVC work?
Router
Controller Model
Browser
View
Request
Dispatch
Fetch dataPush data
Render Response

11. Making an HTTP request
Router
Controller Model
Browser
View
Request
Dispatch
Fetch dataPush data
Render Response

12. Making an HTTP request (cont.)
http://example.com/books/1
GET /books/1 HTTP/1.1
Host: example.com

13. Routing and URL mapping
Router
Controller Model
Browser
View
Request
Dispatch
Fetch dataPush data
Render Response

14. Routing and URL mapping (cont.)
get “admin/news”
match "admin/news", to: "admin#posts", as: "manage_news", via: :get
Prefix Verb URI Pattern Controller#Action
admin_news GET /admin/news admin#news
Prefix Verb URI Pattern Controller#Action
manage_news GET /admin/news admin#posts

15. Routing and URL mapping (cont.)
resources “books”
Note the :id parameter
Prefix Verb URI Pattern Controller#Action
books GET /books books#index
POST /books books#create
new_book GET /books/new books#new
edit_book GET /books/:id/edit books#edit
book GET /books/:id books#show
PATCH /books/:id books#update
PUT /books/:id books#update
DELETE /books/:id books#destroy

16. Migrations, Models and Controllers
Router
Controller Model
Browser
View
Request
Dispatch
Fetch dataPush data
Render Response

17. Migrations, Models and Controllers (cont.)
class CreateBooks < ActiveRecord::Migration
def change
create_table :books do |t|
t.string :title
t.string :isbn
t.integer :pages
end
end
end
$ rails g migration CreateBooks title isbn pages:integer
What is a migration?

18. Migrations, Models and Controllers (cont.)
class BooksController < ApplicationController
...
def show
@book = Book.find(params[:id]) # /books/:id
end
...
end
class Book < ActiveRecord::Base
end

19. Views
Router
Controller Model
Browser
View
Request
Dispatch
Fetch dataPush data
Render Response

20. Views (cont.)
<p>
<strong>Title:</strong>
<%= @book.title %>
</p>
<p>
<strong>ISBN:</strong>
<%= @book.isbn %>
</p>
<p>
<strong>Pages:</strong>
<%= @book.pages %>
</p>
<%= link_to 'Edit', edit_book_path(@book) %> |
<%= link_to 'Back', books_path %>

21. Views (cont.)
<p>
<strong>Title:</strong>
<%= @book.title %>
</p>
<p>
<strong>ISBN:</strong>
<%= @book.isbn %>
</p>
<p>
<strong>Pages:</strong>
<%= @book.pages %>
</p>
<%= link_to 'Edit', edit_book_path(@book) %> |
<%= link_to 'Back', books_path %>
Prefix Verb URI Pattern Controller#Action
books GET /books books#index
edit_book GET /books/:id/edit books#edit

22. The end result

23. Questions?