[OpenLayers-Dev] GML format - unsupported geometry type: box

[Francois Van Der Biest]

Hi list,

Using the recently added getFeatureInfo control + format, I came
across a weird behovior.
It happens while parsing such a GML response, using the default GML format :

<?xml version="1.0" encoding="ISO-8859-1"?>
<msGMLOutput
	 xmlns:gml="http://www.opengis.net/gml"
	 xmlns:xlink="http://www.w3.org/1999/xlink"
	 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
	<Sentiers_littoraux_layer>
		<Sentiers_littoraux_feature>
			<gml:boundedBy>
				<gml:Box srsName="EPSG:2154">
					<gml:coordinates>132292.317102,6855471.709639
135474.476817,6858074.765441</gml:coordinates>
				</gml:Box>
			</gml:boundedBy>
			<DEPARTEMENT>Finistere</DEPARTEMENT>
		</Sentiers_littoraux_feature>
	</Sentiers_littoraux_layer>
</msGMLOutput>

I got such an error : "Unsupported geometry type : Box"
So I opened a ticket [1], and created a patch to parse Box geometries,
as it's currently done for Envelopes.
But I was not really happy nor confident with it, since a Box is not a
true geometry. Yet, Envelopes are currently converted to polygon
geometries...

So, I think we need to choose between those three solutions :
 - either we remove parsing of envelopes and do not commit parsing of
box, beacuse they're not true geometries (option 1)
 - or we commit the parsing of box, which transforms into a polygon
geometry  (option 2)
 - or we create empty geometries, with just their bbox filled. (option
3). In that case, I think we would'nt be able to take into account
envelopes (at least, just their bbox).

All these options break "format reversibility", but, if it's feasible,
option (3) seems the least destructive.
I would personally be in favor of options (3) or (1).
I'd be happy to hear from you on that.

Thank's,
F.

[1] http://trac.openlayers.org/ticket/2191

PS1 : BTW, why are we always using format.GML (and no v2 or v3) to
parse gml getFeatureInfo responses ?
Is it because such responses always conform to GML v1 ? The WMS spec
remains elusive about this.

PS2 : I'm wondering if the above GML response (which is provided by
this mapserver WMS :
http://geolittoral.application.equipement.gouv.fr/wms/metropole) is
correct. Does GML allow sending a bbox without the true geometry ? Any
GML specialist out there ?