Copyright Peter Bengtsson, mail@peterbe.com, 2013-2016
License: BSD
A Django cache_page
decorator on steroids.
Unlike the stock django.views.decorators.cache.change_page
this decorator makes it possible to set a key_prefixer
that is a callable. This callable is passed the request and if it returns None
the page is not cached.
Also, you can set another callable called post_process_response
(which is passed the response and the request) which can do some additional changes to the response before it's set in cache.
Lastly, you can set post_process_response_always=True
so that the post_process_response
callable is always called, even when the response is coming from the cache.
In your Django views:
from fancy_cache import cache_page
@cache_page(60 * 60)
def myview(request):
return render(request, 'page1.html')
def prefixer(request):
if request.method != 'GET':
return None
if request.GET.get('no-cache'):
return None
return 'myprefix'
@cache_page(60 * 60, key_prefixer=prefixer)
def myotherview(request):
return render(request, 'page2.html')
def post_processor(response, request):
response.content += '<!-- this was post processed -->'
return response
@cache_page(60 * 60,
key_prefixer=prefixer,
post_process_response=post_processor)
def yetanotherotherview(request):
return render(request, 'page3.html')
If you want to you can have django-fancy-cache
record every URL it caches. This can be useful for things like invalidation or curious statistical inspection.
You can either switch this on on the decorator itself. Like this:
Or, more conveniently to apply it to all uses of the cache_page
decorator you can set the default in your settings with:
Now, suppose you have the this option enabled. Now you can do things like this:
There is also another option to this and that is to purge (aka. invalidate) the remembered URLs. You simply all the purge=True
option like this:
Note: Since find_urls()
returns a generator, the purging won't happen unless you exhaust the generator. E.g. looping over it or turning it into a list.
The second way to inspect all recorded URLs is to use the fancy-cache
management command. This is only available if you have added fancy_cache
to your INSTALLED_APPS
setting. Now you can do this:
$ ./manage.py fancy-cache --help
$ ./manage.py fancy-cache
$ ./manage.py fancy-cache /some/searchpath /or/like/*/this.*
$ ./manage.py fancy-cache /some/place/* --purge
$ # or to purge them all!
$ ./manage.py fancy-cache --purge
Note, it will only print out URLs that if found (and purged, if applicable).
The third way to inspect the recorded URLs is to add this to your root urls.py
:
Now, if you visit http://localhost:8000/fancy-cache
you get a table listing every URL that django-fancy-cache
has recorded.
If you have enabled FANCY_REMEMBER_ALL_URLS
you can also enable FANCY_REMEMBER_STATS_ALL_URLS
in your settings. What this does is that it attempts to count the number of cache hits and cache misses you have for each URL.
This counting of hits and misses is configured to last "a long time". Possibly longer than you cache your view. So, over time you can expect to have more than one miss because your view cache expires and it starts over.
You can see the stats whenever you use any of the ways described in the section above. For example like this:
There is obviously a small additional performance cost of using the FANCY_REMEMBER_ALL_URLS
and/or FANCY_REMEMBER_STATS_ALL_URLS
in your project so only use it if you don't have any smarter way to invalidate, for debugging or if you really want make it possible to purge all cached responses when you run an upgrade of your site or something.
The simplest way is to simply run:
$ pip install tox
$ tox
Or to run it without tox
you can simply run:
$ export PYTHONPATH=`pwd`
$ export DJANGO_SETTINGS_MODULE=fancy_tests.tests.settings
$ django-admin.py test
(Sorry, been poor in maintaining this. Let's get it right from now)
- 1.0.0
- Drop support for Python <3.5 and Django <2.2.0
- 0.11.0
- Fix for
parse_qs
correctly between Python 2 and Python 3
- Fix for
- 0.10.0
- Fix for keeping blank strings in query strings. #39
- 0.9.0
- Django 1.10 support
- 0.8.2
- Remove deprecated way to define URL patterns and tests in python 3.5
- 0.8.1
- Ability to specify different cache backends to be used peterbe#31
- 0.8.0
- Started keeping a Changelog