[talk-au] Sports Clubs

Roy Wallace waldo000000 at gmail.com
Mon Dec 14 22:34:52 GMT 2009


On Tue, Dec 15, 2009 at 7:02 AM, Steve Bennett <stevagewp at gmail.com> wrote:
> On Tue, Dec 15, 2009 at 7:36 AM, Roy Wallace <waldo000000 at gmail.com> wrote:
>> For example, take a close look at the proposed definition of
>> "member_club" - is it in the form of "if A and B and C, it's a
>> member_club"? If so, isn't it a better solution to *tag* A and B and
>> C? There's no need to create complex definitions. So why do it?
>
> Because otherwise, the logic "if A and B and C then member_club" needs
> to be encoded in each and every renderer.

Ah, I understand your thinking now.

> Now, I don't mind if you
> want to tag the thing "A, B, C, member_club".

Yes, I would prefer to do that.

> But tagging it "A, B, C"
> and expecting all renderers to give you the right result will not
> work. Even less so when you expect a certain icon or something to be
> displayed. Can you think of any examples where it does?
>
> (Oh wait, Roy believes that we shouldn't ever think about renderers,
> they're totally irrelevant. Just tag what you want to tag.)

I think of "renderers" as just one possible class of OSM data "user".
Given this perspective, I'm more concerned with getting the data right
than with getting the rendering right. That's not to say rendering
isn't important. I mean, if you get the data right first, it is then
easier to use (e.g. render) the data. Not the other way around. And,
for me, having A, B and C tagged instead of (or as well as)
"member_club" is much more powerful (in general) for a data user.
There are at least two main reasons why:

1) let say a user wants to find (or render) features that are, say, "A
and B". This isn't easy to do if A and B aren't explicitly tagged, but
only "A, B and C", or "A, not B and generally C", "C but with a gravel
surface", "B except on Tuesdays unless tagged with X", "A and
well-engineered for bicycles", etc.

2) the need for complex tag definitions in the wiki is lessened. I
think this can help us avoid future footway/cycleway-type problems.




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