Known issues (deegree WFS)

The deegree WFS is (of course) not perfect. Some of the issues are implementation related and can be resolved, others stem from more fundamental problems.

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Multiple queries with different srsName-attributes in a GetFeature-request

1. Multiple queries with different srsName-attributes in a GetFeature-request

Please consider the following example GetFeature-request. It targets the Philosopher-example schema and consists of 2 queries:

Query the feature of type "app:Place" with name "Paris".
Query the feature of type "app:Country" with name "France".

<wfs:GetFeature version="1.1.0" xmlns:app="http://www.deegree.org/app" xmlns:wfs="http://www.opengis.net/wfs" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opengis.net/wfs
http://schemas.opengis.net/wfs/1.1.0/wfs.xsd">
  <wfs:Query typeName="app:Place">
    <ogc:Filter>
      <ogc:PropertyIsEqualTo>
        <ogc:PropertyName>app:name</ogc:PropertyName>
        <ogc:Literal>Paris</ogc:Literal>
      </ogc:PropertyIsEqualTo>
    </ogc:Filter>
  </wfs:Query>
  <wfs:Query typeName="app:Country">
    <ogc:Filter>
      <ogc:PropertyIsEqualTo>
        <ogc:PropertyName>app:name</ogc:PropertyName>
        <ogc:Literal>France</ogc:Literal>
      </ogc:PropertyIsEqualTo>
    </ogc:Filter>
  </wfs:Query>
</wfs:GetFeature>

The result looks like this (a bit stripped for brevity):

<wfs:FeatureCollection...>
  <gml:featureMember>
    <!-- Paris -->
    <app:Place gml:id="PLACE_453">
      <app:name>Paris</app:name>
      <app:country>
        <app:Country gml:id="COUNTRY_454">
          <app:name>France</app:name>
          ...
          <app:geom>
            <gml:MultiSurface srsName="EPSG:4326">
            ...
            </gml:MultiSurface>
          </app:geom>
        </app:Country>
      </app:country>
    </app:Place>
  </gml:featureMember>
  <!-- France -->
  <gml:featureMember xlink:href="#COUNTRY_454"/>
</wfs:FeatureCollection>

Note that the Paris-feature contains France as a subfeature. Hence, in the gml:featureMember-element for France in the FeatureCollection, it is referenced using an xlink:href-attribute (alternatively, one could put the explicit feature representation into the gml:featureMember-element and reference it from the Paris-feature with an xlink:href-attribute). NOTE: You are not allowed to list a feature twice in a valid document, because every gml:id attribute in the document must be unique. The only alternative would be to omit the gml:id-attribute for the duplicate feature.

Fine. Using xlink:href saved the day here...

But how do you represent the result to the following request:

Query the feature of type "app:Place" with name "Paris", geometries have to be in EPSG:4326
Query the feature of type "app:Country" with name "France", geometries have to be in EPSG:23031

<wfs:GetFeature version="1.1.0" xmlns:app="http://www.deegree.org/app" xmlns:wfs="http://www.opengis.net/wfs" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opengis.net/wfs
http://schemas.opengis.net/wfs/1.1.0/wfs.xsd">
  <wfs:Query srsName="EPSG:4326" typeName="app:Place">
    <ogc:Filter>
      <ogc:PropertyIsEqualTo>
        <ogc:PropertyName>app:name</ogc:PropertyName>
        <ogc:Literal>Paris</ogc:Literal>
      </ogc:PropertyIsEqualTo>
    </ogc:Filter>
  </wfs:Query>
  <wfs:Query srsName="EPSG:23031" typeName="app:Country">
    <ogc:Filter>
      <ogc:PropertyIsEqualTo>
        <ogc:PropertyName>app:name</ogc:PropertyName>
        <ogc:Literal>France</ogc:Literal>
      </ogc:PropertyIsEqualTo>
    </ogc:Filter>
  </wfs:Query>
</wfs:GetFeature>

If you use an xlink:href attribute in the gml:featureMember element to reference the France-feature, the referenced feature contains the geometry in EPSG:4326. But the France-feature was explicitly requested to use EPSG:23031...

Comments? Propositions?

CategoryDeegree2