4. # defining a function
def say_hello(subject):
print 'Hello, %s' % subject
# calling a function
say_hello('World')
5. # defining a function
def say_hello(subject):
print 'Hello, %s' % subject
# calling a function
say_hello('World')
# defining a class
class HelloSayer(object):
def __init__(self, name):
self.name = name
def say_hello(self):
print 'Hello, %s' % self.name
# creating an object instance
i = HelloSayer('World')
i.say_hello()
6. First-Class Everything
• first-class functions
• can be stored in variables
• can be passed into other functions
• can be returned from functions
• first-class classes
• ditto all the above
11. • a view is a function that takes (at minimum)
an HttpRequest and returns an
HttpResponse
• views usually live in the file views.py
• URLs are routed to views using patterns in
the file urls.py
View Basics
12. # __init__.py intentionally left blank
# models.py intentionally left blank
# views.py
from django.http import HttpResponse
def homepage(request):
return HttpResponse('<html><body><h1>Welcome to website</h1></body></html>')
# urls.py
from django.conf.urls.defaults import *
urlpatterns = patterns('',
(r'^$', 'myapp.views.homepage'),
)
13. # views.py
def user_profile(request, username):
# do useful stuff here...
return HttpResponse('''<html><body>
<h1>Profile for user %s</h1>
</body></html>''' % username)
# urls.py
urlpatterns = patterns('',
(r'^user/(w+)/profile$', 'myapp.views.user_profile'),
)
19. Going off the Beaten Path
• at some point you’ll want to customize the
generic views even more
• wrapping only gets you so far
• what about deeper behavior changes?
• e.g,“delete” should actually flag as
“inactive”
22. # completely made-up example
from django.views.generic.list_detail import ObjectListView
class UserListView(ObjectListView):
def get_queryset(self):
if self.request.GET.get('staff', 'n').lower() == 'y':
return Users.objects.filter(staff=True)
else:
return Users.objects.all()
# meanwhile, in urls.py...
(r'^users$', 'myapp.views.UserListView')
23. # completely made-up example
from django.views.generic.create_update import DeleteObjectView
class DeleteUserView(DeleteObjectView):
def perform_deletion(self, user):
user.is_active = False
user.save()
24. Not a Silver Bullet
• still only allows customization the original
author thought of
• can introduce multithreading issues
• “official” Django views aren’t finished yet
