Geoserver: WFS does not return nodes for columns with null values

Question

GeoServer 2.3 does not return an empty XML node for columns with null values. For example, this is a snippet taken from a WFS response to a CQL query:

<gml:featureMember>
<ems:airports fid="airports.3822">
<ems:IKO>KINL</ems:IKO>
<ems:na3>US24271</ems:na3>
<ems:Name>FALLS INTL</ems:Name>
<ems:Type>Civilian/Public</ems:Type>
<ems:the_geom>...</ems:the_geom>
<ems:Mod_time>2011-09-02T20:17:30.831</ems:Mod_time>
</ems:airports>
</gml:featureMember>
<gml:featureMember>
<ems:airports fid="airports.10117">
<ems:IKO>CKV3</ems:IKO>
<ems:Name>DRYDEN BEST WESTERN (Heli)</ems:Name>
<ems:the_geom>
<gml:Point srsName="http://www.opengis.net/gml/srs/epsg.xml#4326">
<gml:coordinates xmlns:gml="http://www.opengis.net/gml" decimal="." cs="," ts=" ">-92.833333,49.783333</gml:coordinates>
</gml:Point>
</ems:the_geom>
<ems:Mod_time>2011-09-08T16:56:07.334</ems:Mod_time>
<ems:Country>Canada</ems:Country>
<ems:Operator>Best Western Motor Inn</ems:Operator>
<ems:Contact>807-223-3201</ems:Contact>
</ems:airports>
</gml:featureMember>

The second featureMember element is missing the na3 and Type nodes because these are null in the database.

Is there a way to configure GeoServer to return an empty node when it encounters a column with a null value?

Answer 1

Apparently this is by design, as it's a WFS specification. See the relevant discussion:

http://osgeo-org.1560.x6.nabble.com/Why-the-WFS-does-not-return-the-NULL-value-field-td3802398.html

It is suggested in that thread to instead parse the "DescribeFeatureType" response, which does contain all fields.

Now if only there was an OpenLayers Control/Plugin that combined this behavior, I would be happy, but I think I'll be forced to develop it from scratch.

Answer 2

describefeaturetype only returns the columns names. Still, if one column contains null, it does not appear in the response, even if for some rows it does have a value.