[Geojson] FW: Features without geometry

[Sean Gillies]

Andrew, if I were working on a JSON encoding of Atom (like James Snell 
is), I'd add a

  ...
  "where": {"type": Point, "coordinates": [...]}
  ...

to the entry object.

Sean

Andrew Turner wrote:
> So, I'm still not clear if/how GeoJSON is used to just 'add'
> geographic content to larger/richer JSON content. Can an example be
> added for clarity - b/c I will definitely be mixing geographic &
> non-geographic content together.
> 
> Also - regarding omitting vs. null geometry. KML and RSS/Atom both are
> valid without any geometry element. So it seems odd that GeoJSON would
> break that mold to require a null-geometry.
> 
> On 10/3/07, Stephen Battey <Stephen.Battey at dottedeyes.com> wrote:
>>> Would this alleviate the concerns of the original poster, if
>>> we said "must have a property 'geometry', which must be a
>>> GeoJSON Geometry or null" ?
>> Yes, that would certainly help.
>> Although semantically a null geometry means 'this feature has no
>> geometry' I think I can get away with using it to mean 'geometry not
>> specified'. The rationale being: if a client specifically asks not to
>> receive any geometry then the client should know to interpret
>> "geometry": null  as 'geometry not specified'.
>> I think that's a reasonable condition to ask of client applications, and
>> it means clients can use a GeoJSON parser to parse the JSON regardless
>> of whether they query for geometry or centroids, bounding boxes,
>> metadata, etc.
>>
>>
>> >From a purely aesthetic point of view, would it be better to use a
>> consistent syntax for empty/null geometry and properties?
>> We have empty geometry defined as ..
>>         "geometry": null
>> .. and empty properties defined as ..
>>         "properties": {}
>>
>> Actually, now that I'm thinking out loud (well, on paper), maybe the
>> difference is a positive thing. They are, after all, two different types
>> of information.
>> Also, using 'null' clearly indicates "an empty geometry" whereas an
>> empty object might give the impression there is geometry but the data
>> ("type" and "coordinates") was inadvertently omitted when the JSON was
>> constructed.
>>
>> The more I think about it the more I like  "geometry": null
>> I think it is a useful addition to the spec.
>>
>>
>> Steve
>>
>>
>>> -----Original Message-----
>>> From: geojson-bounces at lists.geojson.org
>>> [mailto:geojson-bounces at lists.geojson.org] On Behalf Of
>>> Christopher Schmidt
>>> Sent: 02 October 2007 21:24
>>> To: Sean Gillies
>>> Cc: geojson at lists.geojson.org
>>> Subject: Re: [Geojson] FW: Features without geometry
>>>
>>>
>>> On Tue, Oct 02, 2007 at 01:45:57PM -0600, Sean Gillies wrote:
>>>> Thank you for the correction. I much prefer
>>>>
>>>>    { "geometry": null }
>>>>
>>>> over
>>>>
>>>>    { "geometry": {"type": "Empty", ...} }
>>> I can get down with that. My primary concern is that if it
>>> looks like a duck, it has the same properties as a duck.
>>> Since 'null' doesn't look like a duck, then it doesn't need
>>> to have any particular properties.
>>>
>>> Would this alleviate the concerns of the original poster, if
>>> we said "must have a property 'geometry', which must be a
>>> GeoJSON Geometry or null" ?
>>>
>>> Is there anyone against this?
>>>
>>> http://wiki.geojson.org/index.php?title=GeoJSON_draft_version_
>> 4&diff=153&oldid=151
>>
>> Regards,
>> --
>> Christopher Schmidt
>> MetaCarta
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> 
>