[BangPypers] returning value from a class

[Sidu Ponnappa]

> So you'll actually build a redirection instead of just a response for
> the 3xx status codes?
Aye - the native Ruby HTTP libraries do no support an auto-follow-redirect
feature and I wanted to add that to Wrest. So in Wrest, the Redirection
class is a subclass of Response and overrides Response's default
implementation of the 'follow' method to make this possible in a manner
that's transparent to the end user of the library.

On Wed, Apr 6, 2011 at 7:35 PM, Noufal Ibrahim <noufal at gmail.com> wrote:

> On Wed, Apr 06 2011, Sidu Ponnappa wrote:
>
> >> Why do you want to create a class that doesn't create itself when
> called?
> > It's interesting this came up today - we were just arguing about this
> > at work on Monday. Some of my colleagues are of the opinion that this
> > is a Bad Thing and should never be done. I agree that while it's a bad
> > thing, there are rare occasions where it's still the most elegant
> > solution. After all, the allocator is just a factory - I don't see why
> > it should be treated as something special. As long as you have some
> > rules (like the rules for overriding the default equality method in
> > any OO language) you should be fine.
>
> Yup. It is a factory and seeing it that way makes things
> clearer. However, it's one of those things that comes after messing with
> stuff for a while rather than something taught.
>
>
> > FWIW, these are my two rules:
> > * Don't do it unless there's no other sensible option. Like, absolutely
> > nothing else exists that is more elegant.
>
> I'm not "against" it. Overriding the __new__ method in python (i.e. the
> allocator) is often done while metaclassing to create speciallised
> objects. e.g. with custom accessors and stuff like that.
>
> However, like you said, it's a rule to be broken only when you know what
> you're doing.
>
> > * Ensure that you're returning a sub-class of the class where you're
> > implementing a custom allocator. No returning a different type, and
> > definitely no returning a nil.
>
> This makes sense. Liskov's principle would be honoured and things would
> be more predictable.
>
> > Here's one occasion where I had call to do this. See
> >
> >
> https://github.com/kaiwren/wrest/blob/master/spec/wrest/native/response_spec.rb#L41
> >
> > for the spec and
> >
> >
> https://github.com/kaiwren/wrest/blob/master/lib/wrest/native/response.rb#L43
> >
> > for the code. It's in Ruby, though.
>
> So you'll actually build a redirection instead of just a response for
> the 3xx status codes?
>
> I don't know Wrest and the rest of the code well enough to have an
> opinion on being right or wrong but it does illustrate your point
> though.
>
> [...]
>
>
>
> --
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