[gdal-dev] Namespaces in GMLAS

[Ari Jolma]

I've been looking into a GML file ('akaava:Suojelualue') with ogrinfo 
I've got from a Finnish WFS

https://opaskartta.turku.fi/TeklaOGCWeb/WFS.ashx?request=GetCapabilities

First, the XSD files needed a bit of fixing: link GML to 3.1.1 instead 
of 2.1.2 in opaskartta.turku.fi_Tekl..., and fix [-] to [\-] in 
www.paikkatietopalvelu.fi_gml_yhteiset_2.1.6_yhteiset.xsd

After that, ogrinfo does not complain but does not find anything in the 
GML file. I dug in a bit and it turns out that 
GMLASSchemaAnalyzer::Analyze did not use the correct schema files (gml, 
asemakaava, etc) in the 2nd and 3rd passes it does through the 
namespaces -- it did in the first pass. For some reason only the 
namespace -> schema pairs in the GML get into aoNamespaces array. The 
correct ones are available in oMapURIToPrefixWithEmpty.

Probably the way Tekla constructs the GML file is unusual (my guess, I'm 
no expert on this subject). The xsi:schemaLocation in the GML file 
contains only two pairs: wfs -> wfs-schema and kuntagml -> describe 
featuretype request URL. These are in aoNamespaces. The latter then 
imports the gml and asemakaava schemas.

Modifying the code to read the namespaces in the 2nd and 3rd pass 
similarly as in 1st pass I get a long list of layers with ogrinfo and 
can read something real out of the GML file with ogr2ogr. However, 
there's two HTTP 404 errors -- probably some schemas are not where 
expected(?).

Could you Even sched some light on what's going on?

Thanks,

Ari