[Geojson] Features without geometry
Stephen.Battey at dottedeyes.com
Wed Sep 19 02:22:51 PDT 2007
I'm looking into integrating GeoJSON into our web mapping application to
replace the JSON data structure we currently use, which does not follow
One problem I foresee in adopting GeoJSON is there is no option to omit
geometry from features. The GeoJSON spec states:
3-4-1 A feature object must have a member with the name "geometry".
However, there are instances where we would like to transfer feature
information without defining the geometry of those features, which would
just add extra overhead.
For example, our client application has a "get info" tool, where the
client will request information for features at or near a point or
region. The response from the server is a set of features but for the
purposes of this action the geometries of the features is irrelevant.
The client application just wants to retrieve the properties of the
features and display them to the end user.
Our mapping application currently allows the client to specify in the
request whether they would like geometry information included in the
response. Historically, this is because we originally used GML, so
having geometry in the response made the response roughly 110% larger
than without. Although GeoJSON will be significantly smaller than GML
the same logic still applies - the response is roughly 70% larger with
geometry than without.
Does it make sense to omit the geometry member in GeoJSON? Should
geometry be treated as just another piece of information or is it more
fundamental to the definition of a feature?
Conversely, does it make sense for a GeoJSON parser to throw out data as
invalid GeoJSON simply because the geometry information is missing when
all other aspects of the GeoJSON structure are correct - so the parser
could continue parsing, having set the geometry attribute to null or
Software Engineer, Development Team, Dotted Eyes Ltd
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Hanbury Court, Harris Business Park,
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