for basichash (heh) on #django IRC

hashids.py

from hashids import Hashids



class Property(...):
    """ to get the hash in a template {{ myobj.urlsafe_id }} """
    """ to get the URL in a template, {{ myobj.get_absolute_url }} """
    
    # I've shoved this here because why not, but you could put it in module 
    # scope for the whole set of models, or in utils for whole package access.
    hashid_generator = Hashids(...)
    
    def urlsafe_id(self):
        return self.hashid_generator.encrypt(self.pk)

    # Aliased, just like `id` = `pk`
    urlsafe_pk = urlsafe_id

    def get_absolute_url(self):
        return reverse('myapp:myview', kwargs={'hash': self.urlsafe_id()})
        
        
urlpatterns = (
    url('path/(?P<hash>[a-zA-Z0-9]+)/...', View.as_view(), 'myview')
)


class MyView(...):
    def get_object(self, *args, **kwargs):
        """
        for simplicity's sake, I haven't made reference to the parent 
        get_object at all, but the key here is to decrypt the kwarg and if it
        returns something that isn't (), try it against a get_object implementation
        """
        decrypted = Property.hashid_generator.decrypt(self.kwargs.get('hash'))
        if decrypted:
            try:
                Property.objects.get(pk=decrypted)
            except Property.DoesNotExist:
                raise Http404('Invalid Property after hash was decrypted')
        raise Http404('Invalid hash')