Re: [openvrml-develop] Considering renaming node_class

[Braden M. <br...@en...>]

On Sat, 2005-11-19 at 16:25 -0500, Reed Hedges wrote:
> I looked at node_class a bit but don't remember exactly how it works,
> but "factory" does imply a specific way of operating.  Could a
> node_metatype in fact be a kind of node_type? Then you could just have
> "nothing but node_types all the way down" :)

A node_class is a factory for node_types. node_class and node_type have
distinct roles. A node_type identifies a subset of the interfaces that
can be supported by a node implementation and is a factory for nodes
that have those interfaces. The node_class gives the node implementation
identity and provides a way of creating node_types.

Different node types can share implementation logic--that's not unique
to OpenVRML; that's just the way VRML97 works. node_class is a place to
hang that shared implementation logic.

> Either way, but yes, I did find the whole idea of node_class a bit
> mysterious at first, partly because I didn't know what _class meant.

I agree it's vague. So is _metatype better? If not, then what?

> Most of us openvrml users won't need to deal with node_class anyway if
> we're not creating new types of nodes, right?  So the documentation
> could just say so and we could skip over it.

That's true to an extent; though API changes that will be going in soon
will raise its visibility a bit: I'll be making it possible to add and
retrieve node_classes to/from a browser instance. Most casual users
probably won't be interested in this functionality; but it does expose a
rather important dimension of flexibility to those who need it.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>