Django cache_page with keys [duplicate] - django

The #cache_page decorator is awesome. But for my blog I would like to keep a page in cache until someone comments on a post. This sounds like a great idea as people rarely comment so keeping the pages in memcached while nobody comments would be great. I'm thinking that someone must have had this problem before? And this is different than caching per url.
So a solution I'm thinking of is:
#cache_page( 60 * 15, "blog" );
def blog( request ) ...
And then I'd keep a list of all cache keys used for the blog view and then have way of expire the "blog" cache space. But I'm not super experienced with Django so I'm wondering if someone knows a better way of doing this?

This solution works for django versions before 1.7
Here's a solution I wrote to do just what you're talking about on some of my own projects:
def expire_view_cache(view_name, args=[], namespace=None, key_prefix=None):
"""
This function allows you to invalidate any view-level cache.
view_name: view function you wish to invalidate or it's named url pattern
args: any arguments passed to the view function
namepace: optioal, if an application namespace is needed
key prefix: for the #cache_page decorator for the function (if any)
"""
from django.core.urlresolvers import reverse
from django.http import HttpRequest
from django.utils.cache import get_cache_key
from django.core.cache import cache
# create a fake request object
request = HttpRequest()
# Loookup the request path:
if namespace:
view_name = namespace + ":" + view_name
request.path = reverse(view_name, args=args)
# get cache key, expire if the cached item exists:
key = get_cache_key(request, key_prefix=key_prefix)
if key:
if cache.get(key):
# Delete the cache entry.
#
# Note that there is a possible race condition here, as another
# process / thread may have refreshed the cache between
# the call to cache.get() above, and the cache.set(key, None)
# below. This may lead to unexpected performance problems under
# severe load.
cache.set(key, None, 0)
return True
return False
Django keys these caches of the view request, so what this does is creates a fake request object for the cached view, uses that to fetch the cache key, then expires it.
To use it in the way you're talking about, try something like:
from django.db.models.signals import post_save
from blog.models import Entry
def invalidate_blog_index(sender, **kwargs):
expire_view_cache("blog")
post_save.connect(invalidate_portfolio_index, sender=Entry)
So basically, when ever a blog Entry object is saved, invalidate_blog_index is called and the cached view is expired. NB: haven't tested this extensively, but it's worked fine for me so far.

The cache_page decorator will use CacheMiddleware in the end which will generate a cache key based on the request (look at django.utils.cache.get_cache_key) and the key_prefix ("blog" in your case). Note that "blog" is only a prefix, not the whole cache key.
You can get notified via django's post_save signal when a comment is saved, then you can try to build the cache key for the appropriate page(s) and finally say cache.delete(key).
However this requires the cache_key, which is constructed with the request for the previously cached view. This request object is not available when a comment is saved. You could construct the cache key without the proper request object, but this construction happens in a function marked as private (_generate_cache_header_key), so you are not supposed to use this function directly. However, you could build an object that has a path attribute that is the same as for the original cached view and Django wouldn't notice, but I don't recommend that.
The cache_page decorator abstracts caching quite a bit for you and makes it hard to delete a certain cache object directly. You could make up your own keys and handle them in the same way, but this requires some more programming and is not as abstract as the cache_page decorator.
You will also have to delete multiple cache objects when your comments are displayed in multiple views (i.e. index page with comment counts and individual blog entry pages).
To sum up: Django does time based expiration of cache keys for you, but custom deletion of cache keys at the right time is more tricky.

I wrote Django-groupcache for this kind of situations (you can download the code here). In your case, you could write:
from groupcache.decorators import cache_tagged_page
#cache_tagged_page("blog", 60 * 15)
def blog(request):
...
From there, you could simply do later on:
from groupcache.utils import uncache_from_tag
# Uncache all view responses tagged as "blog"
uncache_from_tag("blog")
Have a look at cache_page_against_model() as well: it's slightly more involved, but it will allow you to uncache responses automatically based on model entity changes.

With the latest version of Django(>=2.0) what you are looking for is very easy to implement:
from django.utils.cache import learn_cache_key
from django.core.cache import cache
from django.views.decorators.cache import cache_page
keys = set()
#cache_page( 60 * 15, "blog" );
def blog( request ):
response = render(request, 'template')
keys.add(learn_cache_key(request, response)
return response
def invalidate_cache()
cache.delete_many(keys)
You can register the invalidate_cache as a callback when someone updates a post in the blog via a pre_save signal.

This won't work on django 1.7; as you can see here https://docs.djangoproject.com/en/dev/releases/1.7/#cache-keys-are-now-generated-from-the-request-s-absolute-url the new cache keys are generated with the full URL, so a path-only fake request won't work. You must setup properly request host value.
fake_meta = {'HTTP_HOST':'myhost',}
request.META = fake_meta
If you have multiple domains working with the same views, you should cycle them in the HTTP_HOST, get proper key and do the clean for each one.

Django view cache invalidation for v1.7 and above. Tested on Django 1.9.
def invalidate_cache(path=''):
''' this function uses Django's caching function get_cache_key(). Since 1.7,
Django has used more variables from the request object (scheme, host,
path, and query string) in order to create the MD5 hashed part of the
cache_key. Additionally, Django will use your server's timezone and
language as properties as well. If internationalization is important to
your application, you will most likely need to adapt this function to
handle that appropriately.
'''
from django.core.cache import cache
from django.http import HttpRequest
from django.utils.cache import get_cache_key
# Bootstrap request:
# request.path should point to the view endpoint you want to invalidate
# request.META must include the correct SERVER_NAME and SERVER_PORT as django uses these in order
# to build a MD5 hashed value for the cache_key. Similarly, we need to artificially set the
# language code on the request to 'en-us' to match the initial creation of the cache_key.
# YMMV regarding the language code.
request = HttpRequest()
request.META = {'SERVER_NAME':'localhost','SERVER_PORT':8000}
request.LANGUAGE_CODE = 'en-us'
request.path = path
try:
cache_key = get_cache_key(request)
if cache_key :
if cache.has_key(cache_key):
cache.delete(cache_key)
return (True, 'successfully invalidated')
else:
return (False, 'cache_key does not exist in cache')
else:
raise ValueError('failed to create cache_key')
except (ValueError, Exception) as e:
return (False, e)
Usage:
status, message = invalidate_cache(path='/api/v1/blog/')

I had same problem and I didn't want to mess with HTTP_HOST, so I created my own cache_page decorator:
from django.core.cache import cache
def simple_cache_page(cache_timeout):
"""
Decorator for views that tries getting the page from the cache and
populates the cache if the page isn't in the cache yet.
The cache is keyed by view name and arguments.
"""
def _dec(func):
def _new_func(*args, **kwargs):
key = func.__name__
if kwargs:
key += ':' + ':'.join([kwargs[key] for key in kwargs])
response = cache.get(key)
if not response:
response = func(*args, **kwargs)
cache.set(key, response, cache_timeout)
return response
return _new_func
return _dec
To expired page cache just need to call:
cache.set('map_view:' + self.slug, None, 0)
where self.slug - param from urls.py
url(r'^map/(?P<slug>.+)$', simple_cache_page(60 * 60 * 24)(map_view), name='map'),
Django 1.11, Python 3.4.3

FWIW I had to modify mazelife's solution to get it working:
def expire_view_cache(view_name, args=[], namespace=None, key_prefix=None, method="GET"):
"""
This function allows you to invalidate any view-level cache.
view_name: view function you wish to invalidate or it's named url pattern
args: any arguments passed to the view function
namepace: optioal, if an application namespace is needed
key prefix: for the #cache_page decorator for the function (if any)
from: http://stackoverflow.com/questions/2268417/expire-a-view-cache-in-django
added: method to request to get the key generating properly
"""
from django.core.urlresolvers import reverse
from django.http import HttpRequest
from django.utils.cache import get_cache_key
from django.core.cache import cache
# create a fake request object
request = HttpRequest()
request.method = method
# Loookup the request path:
if namespace:
view_name = namespace + ":" + view_name
request.path = reverse(view_name, args=args)
# get cache key, expire if the cached item exists:
key = get_cache_key(request, key_prefix=key_prefix)
if key:
if cache.get(key):
cache.set(key, None, 0)
return True
return False

Instead of using the cache page decorator, you could manually cache the blog post object (or similar) if there are no comments, and then when there's a first comment, re-cache the blog post object so that it's up to date (assuming the object has attributes that reference any comments), but then just let that cached data for the commented blog post expire and then no bother re-cacheing...

Instead of explicit cache expiration you could probably use new "key_prefix" every time somebody comment the post. E.g. it might be datetime of the last post's comment (you could even combine this value with the Last-Modified header).
Unfortunately Django (including cache_page()) does not support dynamic "key_prefix"es (checked on Django 1.9) but there is workaround exists. You can implement your own cache_page() which may use extended CacheMiddleware with dynamic "key_prefix" support included. For example:
from django.middleware.cache import CacheMiddleware
from django.utils.decorators import decorator_from_middleware_with_args
def extended_cache_page(cache_timeout, key_prefix=None, cache=None):
return decorator_from_middleware_with_args(ExtendedCacheMiddleware)(
cache_timeout=cache_timeout,
cache_alias=cache,
key_prefix=key_prefix,
)
class ExtendedCacheMiddleware(CacheMiddleware):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
if callable(self.key_prefix):
self.key_function = self.key_prefix
def key_function(self, request, *args, **kwargs):
return self.key_prefix
def get_key_prefix(self, request):
return self.key_function(
request,
*request.resolver_match.args,
**request.resolver_match.kwargs
)
def process_request(self, request):
self.key_prefix = self.get_key_prefix(request)
return super().process_request(request)
def process_response(self, request, response):
self.key_prefix = self.get_key_prefix(request)
return super().process_response(request, response)
Then in your code:
from django.utils.lru_cache import lru_cache
#lru_cache()
def last_modified(request, blog_id):
"""return fresh key_prefix"""
#extended_cache_page(60 * 15, key_prefix=last_modified)
def view_blog(request, blog_id):
"""view blog page with comments"""

Most of the solutions above didn't work in our case because we use https. The source code for get_cache_key reveals that it uses request.get_absolute_uri() to generate the cache key.
The default HttpRequest class sets the scheme as http. Thus we need to override it to use https for our dummy request object.
This is the code that works fine for us :)
from django.core.cache import cache
from django.http import HttpRequest
from django.utils.cache import get_cache_key
class HttpsRequest(HttpRequest):
#property
def scheme(self):
return "https"
def invalidate_cache_page(
path,
query_params=None,
method="GET",
):
request = HttpsRequest()
# meta information can be checked from error logs
request.META = {
"SERVER_NAME": "www.yourwebsite.com",
"SERVER_PORT": "443",
"QUERY_STRING": query_params,
}
request.path = path
key = get_cache_key(request, method=method)
if cache.has_key(key):
cache.delete(key)
Now I can use this utility function to invalidate the cache from any of our views:
page = reverse('url_name', kwargs={'id': obj.id})
invalidate_cache_page(path)

Duncan's answer works well with Django 1.9. But if we need invalidate url with GET-parameter we have to make a little changes in request.
Eg for .../?mykey=myvalue
request.META = {'SERVER_NAME':'127.0.0.1','SERVER_PORT':8000, 'REQUEST_METHOD':'GET', 'QUERY_STRING': 'mykey=myvalue'}
request.GET.__setitem__(key='mykey', value='myvalue')

I struggled with a similar situation and here is the solution I came up with, I started it on an earlier version of Django but it is currently in use on version 2.0.3.
First issue: when you set things to be cached in Django, it sets headers so that downstream caches -- including the browser cache -- cache your page.
To override that, you need to set middleware. I cribbed this from elsewhere on StackOverflow, but can't find it at the moment. In appname/middleware.py:
from django.utils.cache import add_never_cache_headers
class Disable(object):
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
response = self.get_response(request)
add_never_cache_headers(response)
return response
Then in settings.py, to MIDDLEWARE, add:
'appname.middleware.downstream_caching.Disable',
Keep in mind that this approach completely disables downstream caching, which may not be what you want.
Finally, I added to my views.py:
def expire_page(request, path=None, query_string=None, method='GET'):
"""
:param request: "real" request, or at least one providing the same scheme, host, and port as what you want to expire
:param path: The path you want to expire, if not the path on the request
:param query_string: The query string you want to expire, as opposed to the path on the request
:param method: the HTTP method for the page, if not GET
:return: None
"""
if query_string is not None:
request.META['QUERY_STRING'] = query_string
if path is not None:
request.path = path
request.method = method
# get_raw_uri and method show, as of this writing, everything used in the cache key
# print('req uri: {} method: {}'.format(request.get_raw_uri(), request.method))
key = get_cache_key(request)
if key in cache:
cache.delete(key)
I didn't like having to pass in a request object, but as of this writing, it provides the scheme/protocol, host, and port for the request, pretty much any request object for your site/app will do, as long as you pass in the path and query string.

One more updated version of Duncan's answer: had to figure out correct meta fields: (tested on Django 1.9.8)
def invalidate_cache(path=''):
import socket
from django.core.cache import cache
from django.http import HttpRequest
from django.utils.cache import get_cache_key
request = HttpRequest()
domain = 'www.yourdomain.com'
request.META = {'SERVER_NAME': socket.gethostname(), 'SERVER_PORT':8000, "HTTP_HOST": domain, 'HTTP_ACCEPT_ENCODING': 'gzip, deflate, br'}
request.LANGUAGE_CODE = 'en-us'
request.path = path
try:
cache_key = get_cache_key(request)
if cache_key :
if cache.has_key(cache_key):
cache.delete(cache_key)
return (True, 'successfully invalidated')
else:
return (False, 'cache_key does not exist in cache')
else:
raise ValueError('failed to create cache_key')
except (ValueError, Exception) as e:
return (False, e)

The solution is simple, and do not require any additional work.
Example
#cache_page(60 * 10)
def our_team(request, sorting=None):
...
This will set the response to the cache with the default key.
Expire a view cache
from django.utils.cache import get_cache_key
from django.core.cache import cache
def our_team(request, sorting=None):
# This will remove the cache value and set it to None
cache.set(get_cache_key(request), None)
Simple, Clean, Fast.

Related

Django. 301 Redirect from old URL to new

Hello! Please tell me how to organize a redirect correctly.
There is an old version of the site and a new one. In the old version (another CMS, not Django) the objects have their own URL, in the new revised scheme, and the objects have a different URL.
In each object on the new site, there is a completed field with the old URL. In model.py it looks like this:
old_url = models.CharField('Old URL', blank=True, max_length=100)
I specifically moved the old url to a separate field. Or was it not necessary to do this?
Question. How to set up a redirect correctly, so that after going to the object using the old URL, the site visitor will be redirected to the new URL of this object?
IMHO, I don't think writting old_url for each and every object is pretty inefficient. Instead you can implement a custom 404 view, and handle the redirection there.
I think you can create some regex or plain url maps to new url and redirect accordingly.
import re
from django.http import HttpResponseNotFound
OLD_URL_MAP = { 'old_url_regex': 'new_url_path'}
def handler404(self, request):
for old_re, new_url in OLD_URL_MAP.items():
if re.match(old_re, request.path):
return redirect(new_url, request.resolver_match.kwargs)
return HttpResponseNotFound('not found')
# inside urls.py
handler404 = 'myapp.views.handler404'
Here I have used a map hard coded in python, you can create a model for that as well.
Update
A costly solution is to use middleware. You can try like this:
import re
from django.urls import resolve
OLD_URL_MAP = { 'old_url_regex': 'new_url_path'}
class RerouteMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
try:
resolve(request.path_info) # trying to find if the current url exists in your django project. if not, it will throw exception.
except:
for old_re, new_url in OLD_URL_MAP.items(): # iterating through urls
if re.match(old_re, request.path):
return redirect(new_url, request.resolver_match.kwargs)
response = self.get_response(request)
return response
And add that middleware at the bottom of MIDDLEWARE settings.
FYI, its a regex based solution, assuming those urls are dynamic. Instead you can use plain text urls, but its up to you.
Use redirect() from django.shortcuts [the same library from where you import render]. Also, assuming, that the old_url contains only the relative url.
from django.shortcuts import render, redirect
def someView(request):
q = ~some queryset returning the current object~
current_url = request.get_full_path().strip("http://www.example.com/")
if q.old_url == current_url:
redirect(q.new_url)
else:
pass
Remember, redirect() returns an HttpResponse.

Code to run in all views in a views.py file

What would be the best way of putting a bit of code to run for all views in a views.py file?
I come from a PHP background and I normally put this in the constructor/index bit so that it always ran whatever page is being requested. It has to be specific for that views.py file though, I want to check that the user has access to 'this app/module' and want to avoid having to use decorators on all views if possible?
TL;DR
You should check about middlewares. It allows to execute some code before the view execution, the template rendering and other stuff.
Some words about middlewares
You can represent middlewares in your head like this:
As you can see, the request (orange arrow) go through every middleware before executing the view and then can hitting every middleware after (if you want to do something before the template processing for example).
Using Django 1.10
Arcitecture of middlewares have changed in Django 1.10, and are now represented by simple function. For example, here's a counter of visits for each page:
def simple_middleware(get_response):
# One-time configuration and initialization.
def middleware(request):
try:
p = Page.objects.get(url=request.path)
p.nb_visits += 1
p.save()
except Page.DoesNotExist:
Page(url=request.path).save()
response = get_response(request)
if p:
response.content += "This page has been seen {0} times.".format(p.nb_visits)
return response
return middleware
And voilà.
Using Django
Here's an example of middleware, which would update a counter for each visit of a page (admit that a Page Model exists with two field : url and nb_visits)
class StatsMiddleware(object):
def process_view(self, request, view_func, view_args, view_kwargs):
try:
p = Page.objects.get(url=request.path)
p.nb_visits += 1
p.save()
except Page.DoesNotExist:
Page(url=request.path).save()
def process_response(self, request, response):
if response.status_code == 200:
p = Page.objects.get(url=request.path)
# Let's say we add our info after the html response (dirty, yeah I know)
response.content += u"This page has been seen {0} times.".format(p.nb_visits)
return response
Hopes this will help you :)
Middleware is the solution but keep in mind the the order to define the middleware in the settings.py matters.

Technique for subclassing Django UpdateCacheMiddleware and FetchFromCacheMiddleware

I've used the UpdateCacheMiddleware and FetchFromCacheMiddleware MiddleWare to enable site-wide anonymous caching to varying levels of success.
The biggest problem is that the Middleware only caches an anonymous user's first request. Since a session_id cookie is set on that first response, subsequent requests by that anonymous user do not hit the cache as a result of the view level cache varying on Headers.
My webpages do not meaningfully vary among anonymous users and, in so far as they do vary, I can handle that via Ajax. As a result, I decided to try to subclass Django's caching Middleware to no longer vary on Header. Instead, it varies on Anonymous vs. LoggedIn Users. Because I am using the Auth backend, and that handler occurs before fetching from the cache, it seems to work.
class AnonymousUpdateCacheMiddleware(UpdateCacheMiddleware):
def process_response(self, request, response):
"""
Sets the cache, if needed.
We are overriding it in order to change the behavior of learn_cache_key().
"""
if not self._should_update_cache(request, response):
# We don't need to update the cache, just return.
return response
if not response.status_code == 200:
return response
timeout = get_max_age(response)
if timeout == None:
timeout = self.cache_timeout
elif timeout == 0:
# max-age was set to 0, don't bother caching.
return response
patch_response_headers(response, timeout)
if timeout:
######### HERE IS WHERE IT REALLY GOES DOWN #######
cache_key = self.learn_cache_key(request, response, self.cache_timeout, self.key_prefix, cache=self.cache)
if hasattr(response, 'render') and callable(response.render):
response.add_post_render_callback(
lambda r: self.cache.set(cache_key, r, timeout)
)
else:
self.cache.set(cache_key, response, timeout)
return response
def learn_cache_key(self, request, response, timeout, key_prefix, cache=None):
"""_generate_cache_header_key() creates a key for the given request path, adjusted for locales.
With this key, a new cache key is set via _generate_cache_key() for the HttpResponse
The subsequent anonymous request to this path hits the FetchFromCacheMiddleware in the
request capturing phase, which then looks up the headerlist value cached here on the initial response.
FetchFromMiddleWare calcuates a cache_key based on the values of the listed headers using _generate_cache_key
and then looks for the response stored under that key. If the headers are the same as those
set here, there will be a cache hit and the cached HTTPResponse is returned.
"""
key_prefix = key_prefix or settings.CACHE_MIDDLEWARE_KEY_PREFIX
cache_timeout = self.cache_timeout or settings.CACHE_MIDDLEWARE_SECONDS
cache = cache or get_cache(settings.CACHE_MIDDLEWARE_ALIAS)
cache_key = _generate_cache_header_key(key_prefix, request)
# Django normally varies caching by headers so that authed/anonymous users do not see same pages
# This makes Google Analytics cookies break caching;
# It also means that different anonymous session_ids break caching, so only first anon request works
# In this subclass, we are ignoring headers and instead varying on authed vs. anonymous users
# Alternatively, we could also strip cookies potentially for the same outcome
# if response.has_header('Vary'):
# headerlist = ['HTTP_' + header.upper().replace('-', '_')
# for header in cc_delim_re.split(response['Vary'])]
# else:
headerlist = []
cache.set(cache_key, headerlist, cache_timeout)
return _generate_cache_key(request, request.method, headerlist, key_prefix)
The Fetcher, which is responsible for retrieving the page from the cache, looks like this
class AnonymousFetchFromCacheMiddleware(FetchFromCacheMiddleware):
def process_request(self, request):
"""
Checks whether the page is already cached and returns the cached
version if available.
"""
if request.user.is_authenticated():
request._cache_update_cache = False
return None
else:
return super(SmarterFetchFromCacheMiddleware, self).process_request(request)
There was a lot of copying for UpdateCacheMiddleware, obviously. I couldn't figure out a better hook to make this cleaner.
Does this generally seem like a good approach? Any obvious issues that come to mind?
Thanks,
Ben
You may work around this by temporarily removing unwanted vary fields from response['Vary']:
from django.utils.cache import cc_delim_re
class AnonymousUpdateCacheMiddleware(UpdateCacheMiddleware):
def process_response(self, request, response):
vary = None
if not request.user.is_authenticated() and response.has_header('Vary'):
vary = response['Vary']
# only hide cookie here, add more as your usage
response['Vary'] = ', '.join(
filter(lambda v: v != 'cookie', cc_delim_re.split(vary))
response = super(AnonymousUpdateCacheMiddleware, self).process_response(request, response)
if vary is not None:
response['Vary'] = vary
return response
Also, set CACHE_MIDDLEWARE_ANONYMOUS_ONLY = True in settings to prevent cache for authenticated users.

Django URL Detail

I have to assign to work on one Django project. I need to know about the URL say, http://....
Since with ‘urls.py’ we indeed have ‘raw’ information. How I come to know about the complete URL name; mean with
http+domain+parameters
Amit.
Look at this snippet :
http://djangosnippets.org/snippets/1197/
I modified it like this :
from django.contrib.sites.models import RequestSite
from django.contrib.sites.models import Site
def site_info(request):
site_info = {'protocol': request.is_secure() and 'https' or 'http'}
if Site._meta.installed:
site_info['domain'] = Site.objects.get_current().domain
site_info['name'] = Site.objects.get_current().name
else:
site_info['domain'] = RequestSite(request).domain
site_info['name'] = RequestSite(request).name
site_info['root'] = site_info['protocol'] + '://' + site_info['domain']
return {'site_info':site_info}
The if/else is because of different versions of Django Site API
This snippet is actually a context processor, so you have to paste it in a file called context_processors.py in your application, then add to your settings :
TEMPLATE_CONTEXT_PROCESSORS = DEFAULT_SETTINGS.TEMPLATE_CONTEXT_PROCESSORS + (
'name-of-your-app.context_processors.site_info',
)
The + is here to take care that we d'ont override the possible default context processor set up by django, now or in the future, we just add this one to the tuple.
Finally, make sure that you use RequestContext in your views when returning the response, and not just Context. This explained here in the docs.
It's just a matter of using :
def some_view(request):
# ...
return render_to_response('my_template.html',
my_data_dictionary,
context_instance=RequestContext(request))
HTTPS status would be handled differently by different web servers.
For my Nginx reverse proxy to Apache+WSGI setup, I explicitly set a header that apache (django) can check to see if the connection is secure.
This info would not be available in the URL but in your view request object.
django uses request.is_secure() to determine if the connection is secure. How it does so depends on the backend.
http://docs.djangoproject.com/en/dev/ref/request-response/#django.http.HttpRequest.is_secure
For example, for mod_python, it's the following code:
def is_secure(self):
try:
return self._req.is_https()
except AttributeError:
# mod_python < 3.2.10 doesn't have req.is_https().
return self._req.subprocess_env.get('HTTPS', '').lower() in ('on', '1')
If you are using a proxy, you will probably find it useful that HTTP Headers are available in HttpRequest.META
http://docs.djangoproject.com/en/dev/ref/request-response/#django.http.HttpRequest.META
Update: if you want to log every secure request, use the above example with a middleware
class LogHttpsMiddleware(object):
def process_request(self, request):
if request.is_secure():
protocol = 'https'
else:
protocol = 'http'
print "%s://www.mydomain.com%s" % (protocol, request.path)
Add LogHttpsMiddleware to your settings.py MIDDLEWARE_CLASSES

How to display a custom error page for HTTP status 405 (method not allowed) in Django when using #require_POST

My question is simple, how do I display a custom error page for HTTP status 405 (method not allowed) in Django when using the #require_POST decorator?
I'm using the django.views.decorators.http.require_POST decorator, and when the page is visited by GET request, the console shows a 405 error, but the page is just blank (not even a Django error page). How do I get Django to display a custom and/or default error page for this kind of error?
EDIT:
It's worth mentioning that I've tried putting a 404.html, 500.html and 405.html page in my templates folder - but that does not help either. I have also varied between DEBUG = True and False, to no avail.
You have to write custom Django middleware. You can start with this one and extend it to check if 405.html file exists and so on:
from django.http import HttpResponseNotAllowed
from django.template import RequestContext
from django.template import loader
class HttpResponseNotAllowedMiddleware(object):
def process_response(self, request, response):
if isinstance(response, HttpResponseNotAllowed):
context = RequestContext(request)
response.content = loader.render_to_string("405.html", context_instance=context)
return response
Check docs if you don't know how to install middleware:
http://docs.djangoproject.com/en/dev/topics/http/middleware/
You can also check this article:
http://mitchfournier.com/2010/07/12/show-a-custom-403-forbidden-error-page-in-django/
If you look into the documentation and the source code of django.views.defaults you see that only 404 and 500 errors are supported in a way that you only have to add the 404.html resp. 500.html to your templates directory.
In the doc. you can also read the following
Returning HTTP error codes in Django
is easy. There are subclasses of
HttpResponse for a number of common
HTTP status codes other than 200
(which means "OK"). You can find the
full list of available subclasses in
the request/response documentation.
Thus if you want to return a 405 error, you have to use the HttpResponseNotAllowed class
An example
I'm not sure that's possible. Perhaps you should consider filing a bug report.
I landed here in 2022. The above accepted answer is not working for me. I use django rest framework. My sollution was to create a middleware with
#app/middleware.py
from django.http import HttpResponse
from django.template import loader
class HttpResponseNotAllowedMiddleware:
def __init__(self, get_response):
self.get_response = get_response
# One-time configuration and initialization.
def __call__(self, request):
# Code to be executed for each request before
# the view (and later middleware) are called.
response = self.get_response(request)
# Code to be executed for each request/response after
# the view is called.
if response.status_code == 405:
context = {}
template = loader.get_template('app/405.html')
return HttpResponse(template.render(context, request))
return response
then install it by adding this to settings
MIDDLEWARE = [
.......
'app.middleware.HttpResponseNotAllowedMiddleware',
]
the 405.html template is just a plain not allowed text