[GeoJSON] Aligning implementations

[Tim Schaub]

Hey-

Chris Holmes wrote:
> Ok, I'd like to take a shot at lining up the proto-implementations and 
> perhaps putting some words down on the wiki.
> 
> The big open question for me right now is if geometry is a top level 
> property, as in OpenLayers/PCL at the moment

...

> Or do we want geometry as just one of the properties:

My thinking:

What does every feature have?  Some way to be identified (id), some 
geometry (geometry), and a bunch of other attributes (properties).

Can you have a feature without geometry?  No, that's silly.

Can you have a feature without a title?  Of course.  We're talking about 
the JSON representation of geographic features, not documents.

Ok, I know that's a bit narrow, but continuing in that same vein - if 
I'm writing an application that reads GeoJSON, I'm going to make it 
break if a feature comes in without a geometry.  If a feature comes in 
without a title or a link, I'll continue on without flinching.  That 
suggests to me that geometry and title don't belong in the same place 
(both under properties).

Of course, all of this only becomes a rule if enough people think in the 
same way.

Are things like envelopes and links fundamental components of a 
geographic feature for others?  Obviously, I see utility in more than 
what I've proposed - but I think it makes sense to sort out requirements 
before getting into options.

Tim