Django is a Python web framework that supports rapid development of pragmatic web applications. It allows defining models, views, URLs and templates to structure the application logically. Models define the database schema using Python classes. Views handle requests and return responses like HTML. Templates define presentation logic separately. Django provides a full-featured admin interface and forms to manage data. It aims to strike a balance between high-level features and low-level flexibility.

1. Django
Szalai Ferenc
(szferi@wsbricks.com)

2. Bevezetés

3. “Django egy magas szintű Python
nyelven írt web alkalmazás
keretrendszer, ami a gyors és
pragmatikus alkalmazás fejlesztést
támogatja.”

4. Telepítés

5. előfeltétel: python, django forrás
(svn, tar.gz)
# cd django
# python setup.py install
http://www.djangoproject.com/documentation/install/

6. Alapfogalmak
● Projekt
● Alkalmazas
● Model
● View
● Controller (URL)
● Template

7. $ django-admin.py startproject supporter

8. $ ls -l supporter/
__init__.py
manage.py
settings.py
urls.py

9. $ python manage.py runserver
Validating models...
0 errors found
Django version 1.1 beta 1, using
settings 'supporter.settings'
Development server is running at
http://127.0.0.1:8000/
Quit the server with CONTROL-C.

10. settings.py
● DATABASE_ENGINE
● DATABASE_NAME
● DATABASE_USER
● DATABASE_PASSWORD
● DATABASE_HOST
● normál python modul
● a saját konfig paramétereink legyenek
nagybetűsek!
● http://www.djangoproject.com/documentation/settings/

11. Alkalmazások
● logikai egység
● újrafelhasználható
● összetartozó model, view, url
gyűjteménye
● $ python manage.py startapp topic

12. $ ls topic/
__init__.py
models.py
tests.py
views.py

13. INSTALLED_APPS = (
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'supporter.topic'
)

14. User
Company
django.contrib.auth
Topic
Topic
djangon.contrib.comment Topic
Comment supporter.topic
Comment

15. Model

16. BEGIN;
CREATE TABLE "topic_topic" (
"id" integer NOT NULL PRIMARY KEY,
"author_id" integer NOT NULL,
"type" varchar(1) NOT NULL,
"title" varchar(128) NOT NULL,
"content" text NOT NULL,
"feeling" integer NOT NULL
)
;
COMMIT;

17. Az SQL csúnya
A Python cool

18. from django.db import models
from django.contrib.auth.models import User
class Topic(models.Model):
TOPIC_TYPES = (
('Q', 'Question'),
('I', 'Idea'),
('P', 'Problem'),
)
author = models.ForeignKey(User)
type = models.CharField(max_length=1,
choices=TOPIC_TYPES)
title = models.CharField(max_length=128)
content = models.TextField()
feeling = models.IntegerField()
created = models.DateTimeField(auto_now_add=True)

19. $ python manage.py validate
$ python manage.py syncdb
Creating table auth_permission
Creating table auth_group
Creating table auth_user
Creating table auth_message
Creating table django_content_type
Creating table django_session
Creating table django_site
Creating table topic_topic
You just installed Django's auth system, which
means you don't have any superusers defined.
Would you like to create one now? (yes/no): yes
Username (Leave blank to use 'szferi'):
E-mail address: szferi@wsbricks.com
Password:
Password (again):
Superuser created successfully.
Installing index for auth.Permission model
Installing index for auth.Message model
Installing index for topic.Topic model

20. Model API

21. $ python manage.py shell
In [1]: from supporter.topic.models import Topic
In [2]: from django.contrib.auth.models import User
In [3]: u = User.objects.get(id=1)
In [4]: print u
szferi
In [5]: t = Topics.objects.create(author=u, type='Q',
title='test', content='nagybaj!', feeling=-1)
In [6]: print t
Topic object
In [7]: print t.title
test
In [8]: print Topic.objects.all()
[<Topic: Topic object>]
In [9]: ts = Topic.objects.filter(content__contains='baj')
In [10]: print ts[0].content
nagybaj!

22. class Topic(models.Model):
...
def __unicode__(self):
return self.title

23. $ python manage.py shell
In [1]: from supporter.topic.models import Topic
In [2]: print Topic.objects.all()
[<Topic: test>]

24. class Topic(models.Model):
...
class Meta:
ordering = ['created']

25. Relációk

26. from django.db import models
from django.contrib.auth.models import User
class Topic(models.Model):
TOPIC_TYPES = (
('Q', 'Question'),
('I', 'Idea'),
('P', 'Problem'),
)
author = models.ForeignKey(User)
type = models.CharField(max_length=1,
choices=TOPIC_TYPES)
title = models.CharField(max_length=128)
content = models.TextField()
feeling = models.IntegerField()
created = models.DateTimeField(auto_now_add=True)

27. $ python manage.py shell
In [2]: from django.contrib.auth.models import User
In [3]: u = User.objects.get(id=1)
In [4]: print u
szferi
In [5]: print u.topic_set.all()
[<Topic: test>]
In [6]: print u.topic_set.filter(type='Q')
[<Topic: test>]

28. Views

29. from django.http import HttpResponse
def index(request):
return HttpResponse('Hello!')

30. intermezzó: URL

33. /customer/account/1/contacts/2/

34. from django.conf.urls.defaults import *
import views
urlpatterns = patterns('',
(r'^$', views.index),
(r'^(?P<topic>[0-9]*)/$', views.detail)
)

35. from django.conf.urls.defaults import *
urlpatterns = patterns('',
(r'^topic/', include('supporter.topic.urls')),
)

36. Összetettebb View-k

37. from django.http import
HttpResponse
from supporter.topic.models
import Topic
def index(request):
r = '<ul>'
topics = Topic.objects.all()
for t in topics:
r += "<li>%s</li>" %
t.title
r += '</ul>'
return HttpResponse(r)

38. intermezzó 2: Tempalte

39. <html>
<body>
<p>There is {{ topics|length }} topics</p>
<ul>
{% for t in topics %}
<li>{{ t.title }}</li>
{% endfor %}
</ul>
</body>
</html>

41. Django Admin

42. from django.conf.urls.defaults import *
from django.contrib import admin
admin.autodiscover()
urlpatterns = patterns('',
(r'^admin/', include(admin.site.urls)),
(r'^topic/', include('supporter.topic.urls')),
)

45. Formok

46. from models import Topic
from django.forms import ModelForm
class TopicForm(ModelForm):
class Meta:
model = Topic
exclude = ('author', )

47. def add(request):
from forms import TopicForm
from django.http import HttpResponseRedirect
from django.contrib.auth.models import User
if request.method == 'POST':
form = TopicForm(request.POST)
if form.is_valid():
topic = form.save(commit=False)
topic.author = User.objects.get(id=1)
topic.save()
return HttpResponseRedirect('/')
else:
form = TopicForm()
return render_to_response('add.html',
{'form': form })

48. <html>
<body>
<form method="post" action=".">
{{ form }}
<input type="submit" value="SAVE"
name="save"/>
</form>
</body>
</html>

49. Hova tovább, hovatovább
● automatikus teszt
● saját template tag és filter
● session kezelés
● authentikáció
● cache
● l10n, i18n
● RSS/Atom
● Generikus view-k
● stb, stb.