Web frameworks like Ruby on Rails and Django were created to simplify web development and address common problems. They utilize the Model-View-Controller pattern to separate the database, user interface, and application logic. This improves scalability and maintainability. Frameworks automate common tasks, provide built-in security features, and allow mapping of URLs to code for flexible routing. While not perfect solutions, web frameworks streamline development by handling infrastructure concerns so developers can focus on their specific applications.

1. Web Frameworks
By: Rahul Malik

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

3. Awesome, what are my
options??

4. 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
!quot;#$%&'&$ ())* +,
finding out about ruby

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

6. 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)

7. How do they fix these
problems?

8. Model View Controller
Design
Model Controller View

9. Model

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

11. 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=quot;Use raw HTML.quot;)
body = models.TextField(help_text=quot;Use raw HTML.quot;)
author = models.CharField(maxlength=100)
Entry.objects.get(headline=’framework talk’)
Entry.objects.filter(pub_date=datetime.now())

12. View

13. 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

14. Template Systems
{% extends quot;creator/base.htmlquot; %}
{% block content %}
<h1>User Settings</h1>
<h2>{{ user.username }}</h2>
<form action=quot;.quot; method=quot;postquot;>
{{ form.as_p }}
<input type=quot;submitquot; value=quot;Save Changesquot; />
</form>
{% endblock %}

15. Controller

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

17. 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-]+)/$'

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

19. 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)
)

20. 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),
)

21. Freebies

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

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

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

25. But does it scale?

26. Yes

27. Any Other Questions?