The following three classes provide much of the functionality needed to create Django views. You may think of them as parent views, which can be used by themselves or inherited from. They may not provide all the capabilities required for projects, in which case there are Mixins and Generic class-based views.
Many of Django’s built-in class-based views inherit from other class-based views or various mixins. Because this inheritance chain is very important, the ancestor classes are documented under the section title of Ancestors (MRO). MRO is an acronym for Method Resolution Order.
The master class-based base view. All other class-based views inherit from this base class.
Method Flowchart
Example views.py:
from django.http import HttpResponse
from django.views.generic import View
class MyView(View):
def get(self, request, *args, **kwargs):
return HttpResponse('Hello, World!')
Example urls.py:
from django.conf.urls import patterns, url
from myapp.views import MyView
urlpatterns = patterns('',
url(r'^mine/$', MyView.as_view(), name='my-view'),
)
Attributes
The list of HTTP method names that this view will accept.
Default:
['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
Methods
Returns a callable view that takes a request and returns a response:
response = MyView.as_view()(request)
The view part of the view – the method that accepts a request argument plus arguments, and returns a HTTP response.
The default implementation will inspect the HTTP method and attempt to delegate to a method that matches the HTTP method; a GET will be delegated to get(), a POST to post(), and so on.
By default, a HEAD request will be delegated to get(). If you need to handle HEAD requests in a different way than GET, you can override the head() method. See Supporting other HTTP methods for an example.
If the view was called with a HTTP method it doesn’t support, this method is called instead.
The default implementation returns HttpResponseNotAllowed with a list of allowed methods in plain text.
Handles responding to requests for the OPTIONS HTTP verb. Returns a list of the allowed HTTP method names for the view.
Renders a given template, with the context containing parameters captured in the URL.
Ancestors (MRO)
This view inherits methods and attributes from the following views:
Method Flowchart
Example views.py:
from django.views.generic.base import TemplateView
from articles.models import Article
class HomePageView(TemplateView):
template_name = "home.html"
def get_context_data(self, **kwargs):
context = super(HomePageView, self).get_context_data(**kwargs)
context['latest_articles'] = Article.objects.all()[:5]
return context
Example urls.py:
from django.conf.urls import patterns, url
from myapp.views import HomePageView
urlpatterns = patterns('',
url(r'^$', HomePageView.as_view(), name='home'),
)
Context
Redirects to a given URL.
The given URL may contain dictionary-style string formatting, which will be interpolated against the parameters captured in the URL. Because keyword interpolation is always done (even if no arguments are passed in), any "%" characters in the URL must be written as "%%" so that Python will convert them to a single percent sign on output.
If the given URL is None, Django will return an HttpResponseGone (410).
Ancestors (MRO)
This view inherits methods and attributes from the following view:
Method Flowchart
Example views.py:
from django.shortcuts import get_object_or_404
from django.views.generic.base import RedirectView
from articles.models import Article
class ArticleCounterRedirectView(RedirectView):
permanent = False
query_string = True
pattern_name = 'article-detail'
def get_redirect_url(self, *args, **kwargs):
article = get_object_or_404(Article, pk=kwargs['pk'])
article.update_counter()
return super(ArticleCounterRedirectView, self).get_redirect_url(*args, **kwargs)
Example urls.py:
from django.conf.urls import patterns, url
from django.views.generic.base import RedirectView
from article.views import ArticleCounterRedirectView, ArticleDetail
urlpatterns = patterns('',
url(r'^counter/(?P<pk>\d+)/$', ArticleCounterRedirectView.as_view(), name='article-counter'),
url(r'^details/(?P<pk>\d+)/$', ArticleDetail.as_view(), name='article-detail'),
url(r'^go-to-django/$', RedirectView.as_view(url='http://djangoproject.com'), name='go-to-django'),
)
Attributes
The URL to redirect to, as a string. Or None to raise a 410 (Gone) HTTP error.
The name of the URL pattern to redirect to. Reversing will be done using the same args and kwargs as are passed in for this view.
Whether the redirect should be permanent. The only difference here is the HTTP status code returned. If True, then the redirect will use status code 301. If False, then the redirect will use status code 302. By default, permanent is True.
Whether to pass along the GET query string to the new location. If True, then the query string is appended to the URL. If False, then the query string is discarded. By default, query_string is False.
Methods
Constructs the target URL for redirection.
The signature of this method was changed to include *args.
The default implementation uses url as a starting string and performs expansion of % named parameters in that string using the named groups captured in the URL.
If url is not set, get_redirect_url() tries to reverse the pattern_name using what was captured in the URL (both named and unnamed groups are used).
If requested by query_string, it will also append the query string to the generated URL. Subclasses may implement any behavior they wish, as long as the method returns a redirect-ready URL string.
Jul 20, 2015