On 3 Jun 2010, at 17:45, Carl Meyer wrote: > On Jun 2, 6:20 pm, Ben Firshman <b...@firshman.co.uk> wrote: >> Yeah, this idea came up at the sprints, but it's a little too magic for my >> tastes. > > I dunno... is __new__ really more magic than having a __call__ method > that magically copies the instance you call it on? That certainly > breaks my expectations. > > Django doesn't shy away from "magic" in other areas where it makes for > a usable API. The things that happen to model and form fields > certainly violate the initial expectations of a Python programmer; but > it turns out that most people are happy to write readable models and > don't care what's happening under the hood, and those who do care can > learn a little something about metaclasses. Seems to me that __new__ > is a relatively beautiful solution to a thorny problem: it lets people > use class views in all the same ways they use function views while > maintaining thread-safety, it maintains the "callable that returns > HttpResponse" contract, and most people won't ever see or care about > the "magic" that makes it work. > > +1 for __new__.
One advantage of using __call__ over __new__ is passing arguments to __init__. That's handy for lazily configuring views: (r'', DetailView(queryset=Thing.objects.all()) Ben -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-develop...@googlegroups.com. To unsubscribe from this group, send email to django-developers+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
