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Re: POI Core strawman: encoding geography + namespaces/serialisation format

From: Rob Manson <roBman@mob-labs.com>
Date: Thu, 05 May 2011 08:43:54 +1000
To: "public-poiwg@w3.org" <public-poiwg@w3.org>
Message-ID: <1304549034.3037.20343.camel@robslapu>
This raises the question about serialisation format though.

If we're using these types of external namespaces (e.g. gml: atom: etc.
- which I think is a good idea to support) then this is almost
exclusively XML (at the moment).

JSON does not in general support namespaces and many people seem opposed
to this concept. Although, geojson had a go at it with @namespaces [1]
but this doesn't seem to be actually specified anywhere.  And there's
been a bit of debate and a few proposals that got shouted down on the
JSON Schema list, etc.

If we go with the simple model outlined in the wiki link [1] then we
could benefit from all these existing namespaces/data models and have a
relatively consistent model across both XML and JSON...along with making
it more extensible.


roBman


[1] http://wiki.geojson.org/GeoJSON_draft_version_6#Including_additional_members


On Wed, 2011-05-04 at 14:21 -0400, Raj Singh wrote:
> Here are notes on modifying geometry to harmonize with the W3C Geospatial Vocabulary report [1] and GeoRSS [2]
> 
> [1] http://www.w3.org/2005/Incubator/geo/XGR-geo-20071023/
> [2] http://www.georss.org/gml
> 
> There's more specifying to do here, put I've put some examples below.
> 
> CHANGE:
> <point latitude="42.360890561289295" longitude="-71.09139204025269"/>
> TO:
> <gml:Point><gml:pos>42.360890561289295 -71.09139204025269</gml:pos></gml:Point>
> 
> CHANGE:
> <point id="mainpoint" latitude="27.174799" longitude="78.042111" altitude="10m"/>
> TO:
> <gml:Point id="mainpoint" srsName="urn:ogc:def:crs:EPSG:6.6:4979" srsDimension="3">
> 	<gml:pos>27.174799 78.042111 10</gml:pos>
> </gml:Point>
> 
> reference: http://www.georss.org/gml
> "If your GeoRSS GML data is in a coordinate reference system other than lat/lon WGS84 (often technically referred to as EPSG:4236), add in an srsName attribute to your geometry. 3D decimal degrees CRS example The key thing here is to use CRS epsg:4979, specify the srsDimension attribute, and include a third number in your coordinate tuple."
> 
> 
> CHANGE:
> <route>
> 	<point order="0" latitude="42.360890561289295" longitude="-71.09139204025269"/>
> 	<point order="1" latitude="42.361176" longitude="-71.09018"/>
> 	<point order="2" latitude="42.36272976137689" longitude="-71.09049081802368"/>
> 	<point order="3" latitude="42.36318955298668" longitude="-71.09677791595459"/>
> 	<point order="4" latitude="42.363617631805496" longitude="-71.10156297683716"/>
> </route>
> 
> TO:
> <gml:LineString>
> 	<gml:posList>
> 		42.360890561289295 -71.09139204025269 42.361176 -71.09018 42.36272976137689 -71.09049081802368 ...
> 	</gml:posList>
> </gml:LineString>
> 
> CHANGE:
> <area>
> 	<point order="0" latitude="42.360890561289295" longitude="-71.09139204025269"/>
> 	<point order="1" latitude="42.361176" longitude="-71.09018"/>
> 	<point order="2" latitude="42.36272976137689" longitude="-71.09049081802368"/>
> 	<point order="3" latitude="42.36318955298668" longitude="-71.09677791595459"/>
> 	<point order="4" latitude="42.363617631805496" longitude="-71.10156297683716"/>
> 	<point order="5" latitude="42.360890561289295" longitude="-71.09139204025269"/>
> </area>
> 			
> TO:
> <gml:Polygon>
> 	<gml:exterior><gml:LinearRing>
> 		42.360890561289295 -71.09139204025269 42.361176 -71.09018 42.36272976137689 -71.09049081802368 ...
> 	</gml:LinearRing></gml:exterior>
> </gml:Polygon>
> 
> 
> 
> ---
> Raj
> The OGC: Making location count...
> http://www.opengeospatial.org/contact
> 
> 
> 
> 
Received on Wednesday, 4 May 2011 22:44:24 GMT

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