Clearing specific cache in Django

Question

I am using view caching for a django project.

It says the cache uses the URL as the key, so I'm wondering how to clear the cache of one of the keys if a user updates/deletes the object.

An example: A user posts a blog post to domain.com/post/1234/ .. If the user edits that, i'd like to delete the cached version of that URL by adding some kind of delete cache command at the end of the view that saves the edited post.

I'm using:

@cache_page(60 * 60)
def post_page(....):

If the post.id is 1234, it seems like this might work, but it's not:

def edit_post(....):
    # stuff that saves the edits
    cache.delete('/post/%s/' % post.id)
    return Http.....

Answer 1

From django cache docs, it says that cache.delete('key') should be enough. So, it comes to my mind two problems you might have:

1. Your imports are not correct, remember that you have to import cache from the django.core.cache module:

   from django.core.cache import cache
   
   # ...
   cache.delete('my_url')
   

2. The key you're using is not correct (maybe it uses the full url, including "domain.com"). To check which is the exact url you can go into your shell:

   $ ./manage.py shell
   >>> from django.core.cache import cache
   >>> cache.has_key('/post/1234/')
   # this will return True or False, whether the key was found or not
   # if False, keep trying until you find the correct key ...
   >>> cache.has_key('domain.com/post/1234/') # including domain.com ?
   >>> cache.has_key('www.domain.com/post/1234/') # including www.domain.com ?
   >>> cache.has_key('/post/1234') # without the trailing / ?