launchpad-dev team mailing list archive

[Julian Edwards <julian.edwards@xxxxxxxxxxxxx>]

On Monday 26 July 2010 16:01:31 Jonathan Lange wrote:
> > I guess I'm struggling to see how @classmethod is useful then.  In fact,
> > it's dangerous.
> 
> Why do you think it's dangerous?

Because it allows someone to get hold of a new object that is not security 
wrapped.  I don't know why you'd ever want to do that.

> > FWIW I don't think this way of doing things is any better (nor worse,
> > though) than a utility class, is there a reason to avoid those?
> 
> There are a few:
>   * An IFooSet is a poorly defined object, that doesn't do a very good
> job of representing any actual thing in the system

That's not entirely correct - it's used to represent top-level collections in 
the API.

>   * It is actually more work and more boilerplate to have a second
> class implement IFooSet (type it out!)

From what I've seen it's marginal.

>   * This extra work does not buy any meaningful separation of
> concerns. It's very normal to have code that creates an object
> together with the code that defines the behaviour of the object.

That I agree with :)