[gdal-dev] Get WFS attributes form the gml namespace as OGR fields

[Tamas Szekeres]

Hi Even,

Thank you, that could indeed solve the problem.

Best regards,

Tamas


2017-10-20 0:10 GMT+02:00 Even Rouault <even.rouault at spatialys.com>:

> On jeudi 19 octobre 2017 23:56:29 CEST Tamas Szekeres wrote:
> > It looks like DOWNLOAD_SCHEMA=NO would do the trick, but if I use this
> in a
> > VRT file this way it crashes GDAL.
>
> Just fixed the crash (related to the HTTP driver and GDAL_OF_SHARED open
> flag)
>
> You can also prefix the URL with /vsicurl_streaming/ to avoid full
> ingestion
> into memory
>
> >
> > <OGRVRTDataSource>
> >     <OGRVRTLayer name="OKCounties">
> >         <SrcDataSource>
> > http://cstest.coordinatesolutions.com/geoserver/wfs?VERSION=1.1.0&
> amp;REQUES
> > T=GetFeature&TYPENAME=ogi:okcounties&SRSNAME=EPSG:900913
> > </SrcDataSource>
> >         <OpenOptions>
> >             <OOI key="DOWNLOAD_SCHEMA">NO</OOI>
> >         </OpenOptions>
> >         <LayerSRS>EPSG:900913</LayerSRS>
> >         <SrcSQL>SELECT *,
> > 'BRUSH(fc:#00000000);PEN(c:#008000,w:3px);LABEL(f:"Arial",
> c:#008000,s:14px,t
> > :{name})' as OGR_STYLE from "okcounties"</SrcSQL>
> >     </OGRVRTLayer>
> > </OGRVRTDataSource>
> >
> > 2017-10-19 23:18 GMT+02:00 Even Rouault <even.rouault at spatialys.com>:
> > > On jeudi 19 octobre 2017 22:55:50 CEST Tamas Szekeres wrote:
> > > > Hi all,
> > > >
> > > > It looks like whenever we have a dataset (shapefile,db table,etc...)
> > >
> > > which
> > >
> > > > has a
> > > > column with such names like "description", "name", "location"
> GeoServer
> > > > maps it to the elements in the gml namespace (in a 1.1 request),
> > > > therefore DescribeFeatureType doesn't contain these attributes.
> > > >
> > > > For example this response doesn't include the name attribute
> > > >
> > > > http://cstest.coordinatesolutions.com/geoserver/wfs?VERSION=1.1.0&
> > >
> > > SERVICE=WF
> > >
> > > > S&REQUEST=DescribeFeatureType&TYPENAME=ogi:okcounties
> > > >
> > > > However that attribute is returned in the GetFeature request in the
> > > > gml:name section, like:
> > > >
> > > > http://cstest.coordinatesolutions.com/geoserver/wfs?VERSION=1.1.0&
> > >
> > > REQUEST=Ge
> > >
> > > > tFeature&TYPENAME=ogi:okcounties
> > > >
> > > > But as the result of this behaviour the WFS driver doesn't include
> this
> > > > item in the layer definition. Is that possible to retrieve these
> > >
> > > attributes
> > >
> > > > from the WFS driver as OGR fields for example to use them in SQL
> > > > expressions?
> > >
> > > Hi Tamas,
> > >
> > > If your need is to filter on the server, then you'll need to compose
> the
> > > full
> > > URL at hand.
> > > If you want to post-filter, you can downloader the GetFeature request
> and
> > > open
> > > the GML file with the DOWNLOAD_SCHEMA=NO open option (or
> > > GML_DOWNLOAD_WFS_SCHEMA=NO configuration option)
> > > This will prevent the GML driver from trying to use the schema, and
> then
> > > it
> > > will discover the gml:name element.
> > >
> > > OGRFeature(okcounties):155
> > >
> > >   gml_id (String) = okcounties.155
> > >   name (String) = BEAVER
> > >   state (Integer) = 40
> > >   county (Integer) = 7
> > >   stateplane (String) = N
> > >   MULTIPOLYGON (((-100.945566 ....)))
> > >
> > > The XSD parser used by the WFS and GML drivers could also possibly be
> > > modified
> > > to hard-code the definition of those few GML fields (although they
> might
> > > depend on the GML version).
> > >
> > >
> > > Otherwise you can also use the GMLAS driver, but the result will be a
> bit
> > > inconvenient to use as it will create a dedicated layer for the name
> > > attribute
> > > (as gml:name can be repeated):
> > >
> > > $ ogrinfo GMLAS:out.xml
> > > INFO: Open of `GMLAS:out.xml'
> > >
> > >       using driver `GMLAS' successful.
> > >
> > > 1: okcounties (Multi Surface)
> > > 2: okcounties_metadataproperty (None)
> > > 3: okcounties_name (None)
> > > 4: location (None)
> > >
> > > OGRFeature(okcounties):1
> > >
> > >   ogr_pkid (String) = 213FC01A8AA5FA1E1ADC65B21904DA34_okcounties_1
> > >   id (String) = okcounties.155
> > >   state (Integer64) = 40
> > >   county (Integer64) = 7
> > >   stateplane (String) = N
> > >   MULTIPOLYGON (((-100.945566....)))
> > >
> > > OGRFeature(okcounties_name):1
> > >
> > >   ogr_pkid (String) = 213FC01A8AA5FA1E1ADC65B21904DA
> 34_okcounties_1_name_1
> > >   parent_ogr_pkid (String) = 213FC01A8AA5FA1E1ADC65B21904DA
> 34_okcounties_1
> > >   value (String) = BEAVER
> > >
> > > Even
> > >
> > >
> > > --
> > > Spatialys - Geospatial professional services
> > > http://www.spatialys.com
>
>
> --
> Spatialys - Geospatial professional services
> http://www.spatialys.com
>
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