Web Frameworks
By: Rahul Malik

What are they?
• In my opinion - “A software framework
that is meant to remove the everyday pain
and redundancy of web development.”

Awesome, what are my
options??

Ruby on Rails (RoR)
• Made at 37 Signals by
DHH
• Paved the way for
framework development
in many other languages
• Written in Ruby
• Credited with people
!\"#$%&'&$ ())* +,
finding out about ruby

Django
• Written in Python -$./0#12
• Similar philosophies as
Rails except they
stress modularity
• Made in Kansas at The 345&645#$12
World Company !\"#$%&'&$ ())* +,

Why do we need them?
• Web Programming was a black art
• Bad Practices were formed
• High coupling of components
• Mind numbing processes had to be done
repeatedly. (i.e. CRUD pages)
• Infrastructure specific (switching to Oracle
= pain)

How do they fix these
problems?

Model View Controller
Design
Model Controller View

Model

Database Management
• Object Relational Mapping (ORM)
• Switching to another database type is just
changing a flag
• Transaction support as well as database
migrations

Database Management
class Entry(models.Model):
pub_date = models.DateTimeField()
slug = models.SlugField(unique_for_date='pub_date')
headline = models.CharField(maxlength=200)
summary = models.TextField(help_text=\"Use raw HTML.\")
body = models.TextField(help_text=\"Use raw HTML.\")
author = models.CharField(maxlength=100)
Entry.objects.get(headline=’framework talk’)
Entry.objects.filter(pub_date=datetime.now())

View

Template Systems!
• Simple systems that can be used to
generate HTML, CSS, RSS, or any other
text based formats
• Controller provides context and separation
from model
• Good for designers

Template Systems
{% extends \"creator/base.html\" %}
{% block content %}
<h1>User Settings</h1>
<h2>{{ user.username }}</h2>
<form action=\".\" method=\"post\">
{{ form.as_p }}
<input type=\"submit\" value=\"Save Changes\" />
</form>
{% endblock %}

Controller

Sexy URL’s
• blog.php?month=11&day=19&year=2008
• blog/11/19/2008/

Request Routing
• All HTTP Requests get mapped to a
controller or 404 by naming conventions
(rails) or regex matching (django)
• domain.com/blog/view/getvar1/getvar2/...
• '^(?P<year>\\d{4})/(?P<month>[a-z]{3})/(?
P<day>\\w{1,2})/(?P<slug>[\\w-]+)/$'

Request Routing
• Naming Conventions vs. Regex Matching
• What else to you get?
• GET, POST variables, as much HTTP
Header information that you could want

URL Matching (Regex)
from feeds.views import publish_templatized_feed_item, publish_feed_item, refresh_feed
urlpatterns = patterns('',
(r'^publish/$', publish_feed_item),
(r'^publish/template/$', publish_templatized_feed_item),
(r'^refresh/$', refresh_feed)
)

URL Matching (regex)
urlpatterns = patterns('django.views.generic.date_based',
(r'^(?P<year>\\d{4})/(?P<month>[a-z]{3})/(?P<day>\\w{1,2})/(?P<slug>[\\w-]+)/$',
'object_detail', dict(info_dict, slug_field='slug')),
(r'^(?P<year>\\d{4})/(?P<month>[a-z]{3})/(?P<day>\\w{1,2})/$', 'archive_day', info_dict),
(r'^(?P<year>\\d{4})/(?P<month>[a-z]{3})/$', 'archive_month', info_dict),
(r'^(?P<year>\\d{4})/$', 'archive_year', info_dict),
(r'^/?$', 'archive_index', info_dict),
)

Freebies

Automation
• CRUD or Admin interfaces
• Schema Upgrades and Downgrades
(Migrations)
• Generating Frequent Components (new
controller, model, etc.)

Security
• Authorization and Authentication of users
built-in!
• Permissions Models
• Basic Web Security at it’s core (SQL
Injection, CSRF, etc.)

Caching
• Simple hooks and/or helpers baked in
• Flat-File, Database, or Distributed
(memcached) database management

But does it scale?

Yes

Any Other Questions?