Cache a django view that has URL parameters.

Question

I have recently implemented Django's excellent cache framework. However from what I understand Django will not cache a view that is passed parameters in a get request. I have an Ajax view that is passed get parameters that I would like to cache for X seconds, what would be an easy way to do this?

In psuedo code I currently have a URL:

http://mysites/ajaxthing/?user=foo&items=10

I would like to cache any this url as long as it has the same get parameters.

I'm currently using the cache decorators in my view:

myview(stuff)

myview = cache_page(myview, 60 * 3)

I did read about django's vary headers but it went a little over my head, and I'm not even sure its the correct solution

Answer 1

Right, vary headers is not the correct solution, it's used when you want to cache based on client request headers like user-agent etc.

You'll need to use low-level API or template fragment caching. It depends on your views really.

With low-level API it looks something like this:

from django.core.cache import cache

def get_user(request):
    user_id = request.GET.get("user_id")
    user = cache.get("user_id_%s"%user_id)
    if user is None:
        user = User.objects.get(pk=user_id)
        cache.set("user_id_%s"%user_id, user, 10*60) # 10 minutes
    ...
    ..
    .

Answer 2

a bit late, but you can use django-view-cache-utils for that.

Answer 3

Yes, you can use django-view-cache-utils, here is code for your case:

from view_cache_utils import cache_page_with_prefix
from django.utils.hashcompat import md5_constructor
...
@cache_page_with_prefix(60*15, lambda request: md5_constructor(str(request.GET)).hexdigest())
def my_view(request):
    ...