Introduction to Django

Django
"""The Web framework for perfectionists with
deadlines."""
"""Django is a high-level Python Web
framework that encourages rapid development
and clean, pragmatic design."""
https://www.djangoproject.com/

What is inside?
● Built-in ORM(Object-relational Mapper)
● Simple but powerful URL system
● Built-in template system
● I10n(Internationalization)
● Cache system
● Built-in authentication system
● Built-in webserver(for development)
● Automatic admin interface

MVT not MVC
● Model
○ defines the data structure
○ takes care for querying the database
● View
○ defines what data should be presented
○ returns HTTP response
● Template
○ renders the data in suitable format - HTML/XML/etc.

The live of request

Project structure
To start new project run:
django-admin.py startproject my_project
The following structure will be created
my_project/
manage.py
my_project/
__init__.py
settings.py # project settings reside here
urls.py
wsgi.py
This is the default created and good for learning the basics but this way the
settings may be hard to maintain for project in production. Alternative approach
is available at http://ilian.i-n-i.org/django-project-file-structure/.

Application structure
To create new application in you project just run the following command
in the shell:
python manage.py startapp app
The following structure will be created
app/
__init__.py
admin.py # not created automatically before 1.5
models.py
tests.py
views.py
There is no urls.py file but most developer find it useful to keep the application
specific URLs inside it and include them in the main URLs configuration file.

Models
# models.py
from django.db import models
from django.utils.translation import ugettext_lazy as _
class News(models.Model):
title = models.CharField(_('Title'), max_length=255)
slug = models.SlugField(_('Slug'))
content = models.TextField()
To create the tables for the define models just run:
python manage.py syncdb

URLs dispatcher
# urls.py
from django.conf.urls import patterns, url, include
urlpatterns = patterns('',
url(r'^$', 'app.home', name='home'), # give the specific URL meaningful
name
url(r'offers/', include('offers.urls')), # include URLs from another app
(r'^news/$', 'news.views.offers'), # point to specific view
(r'^news/(d{4})/$', 'news.views.year_archive'), # pass arg(s)
(r'^news/(d{4})/(d{2})/$', 'news.views.month_archive'), # pass arg(s)
(r'^news/(?P<slug>[-w]+)/$', 'news.views.single_news'), # pass named args
)
● URLs dispatcher uses regular expression
● The first match found is called
● All arguments are passed as unicode strings

Views
# views.py
from .models import News
from django.shortcuts import get_object_or_404
def single_news(request, slug):
news = get_object_or_404(News.objects.public(), slug=slug)
return render_to_response('news/single_news.html', {'news': news})

Templates
# template.html
{% extends 'my_project/base.html' %}
<h1>{{ news.title }}</h1>
<div class="news-content">
{{ news.content|safe }}
</div>

About Me
eng. Ilian Iliev
● Web Developer for 9+ years
● Python/Django fan for 3+ years
● ilian@i-n-i.org
● http://ilian.i-n-i.org
● https://github.com/IlianIliev/