DescribeFeatureType - accessing schema information - OWS Documenation - User-friendly Desktop Internet GIS

What is DescribeFeatureType?

The DescribeFeatureType WFS operation returns the XSD schema information for a set of FeatureTypes. The schema describes the property names and types associated with the FeatureType.

What is a FeatureType?

A FeatureType is a a single concrete type of gml feature (as defined by an Application Schema .XSD). It is usually named with a "prefix:name" tag to uniquely identify it relative to other FeatureType names.

A FeatureType is often (but not always) synonymous with a dataset or layer. A dataset may contain multiple FeatureTypes - for example, the "City" dataset may contain "ny:Road" and "ny:Building" FeatureTypes.

When to make a DescribeFeatureType request

Make a DescribeFeatureType request when you want to know more detailed information about the schema for a FeatureType. The response will tell you the FeatureType's property names, types, and restrictions.

How to make a DescribeFeatureType request

The DescribeFeatureType request can be made to either:

request the FeatureType schema of a single type
request the FeatureType schema for multiple types

Using HTTP GET:

http://localhost:8080/geoserver/wfs?request=DescribeFeatureType&VERSION=1.0.0&SERVICE=WFS&
                  TYPENAME=cdf:Locks
http://localhost:8080/geoserver/wfs?request=DescribeFeatureType&VERSION=1.0.0&SERVICE=WFS&
                  TYPENAME=cdf:Deletes,cdf:Inserts,cdf:Updates,cdf:Nulls,cdf:Fifteen,cdf:Other,cdf:Seven

You can specify multiple type names (in prefix:name format).

Using HTTP POST:

<?xml version="1.0"?>
<wfs:DescribeFeatureType
              version="1.0.0"
              service="WFS"
              xmlns:wfs="http://www.opengis.net/wfs"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="http://www.opengis.net/wfs../wfs/1.0.0/WFS-basic.xsd">

     <wfs:TypeName>cdf:Deletes</wfs:TypeName>
     <wfs:TypeName>cdf:Inserts</wfs:TypeName>
     <wfs:TypeName>cdf:Updates</wfs:TypeName>
     <wfs:TypeName>cdf:Nulls</wfs:TypeName>
     <wfs:TypeName>cdf:Fifteen</wfs:TypeName>
     <wfs:TypeName>cdf:Seven</wfs:TypeName>

</wfs:DescribeFeatureType>

Format of a DescribeFeatureType response

The response will be an XSD schema file that describes the FeatureType schemas that you requested.

Sample DescribeFeatureType response for cdf:Inserts and cdf:Deletes

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema 
    targetNamespace="http://www.opengis.net/cite/data" 
      xmlns:cdf="http://www.opengis.net/cite/data"
      xmlns:gml="http://www.opengis.net/gml"
      xmlns:xs="http://www.w3.org/2001/XMLSchema"
      elementFormDefault="qualified"
      attributeFormDefault="unqualified" version="1.0">

<xs:import namespace="http://www.opengis.net/gml"
           schemaLocation="http://localhost:8080/geoserver/data/capabilities/gml/2.1.2/feature.xsd"/>

<xs:complexType xmlns:xs="http://www.w3.org/2001/XMLSchema" name="Deletes_Type">
    <xs:complexContent>
        <xs:extension base="gml:AbstractFeatureType">
            <xs:sequence>
                <xs:element name="boundedBy" minOccurs="0" nillable="true" type="gml:PolygonPropertyType"/>
                <xs:element name="id" minOccurs="0" nillable="true" type="xs:string"/>
                <xs:element name="pointProperty" minOccurs="0" nillable="true" type="gml:PointPropertyType"/>

            </xs:sequence>
        </xs:extension>
    </xs:complexContent>
</xs:complexType>
<xs:complexType xmlns:xs="http://www.w3.org/2001/XMLSchema" name="Inserts_Type">
    <xs:complexContent>
        <xs:extension base="gml:AbstractFeatureType">
            <xs:sequence>
                <xs:element name="boundedBy" minOccurs="0" nillable="true" type="gml:PolygonPropertyType"/>
                <xs:element name="id" minOccurs="0" nillable="true" type="xs:string"/>

                <xs:element name="pointProperty" minOccurs="0" nillable="true" type="gml:PointPropertyType"/>
            </xs:sequence>
        </xs:extension>
    </xs:complexContent>
</xs:complexType>

<xs:element name='Inserts' type='cdf:Inserts_Type' substitutionGroup='gml:_Feature'/>
<xs:element name='Deletes' type='cdf:Deletes_Type' substitutionGroup='gml:_Feature'/>


</xs:schema>

Both cdf:Deletes and cdf:Inserts have the same schema -

Property Name	PropertyType
boundedBy	GML Polygon
id	string
pointProperty	GML Point Geometry

How to read an XSD schema file

The Interpreting XML-GML and XSD-Schema portion of this documentation that describes XML and XSD schemas.

Describing FeatureTypes in multiple namespaces!

It is not legal for an XSD schema file to contain the schema of objects in multiple namespaces. In order to get around this, the DescribeFeatureType will generate a schema file which includes multiple other schema files. This is an example response for a request for FeatureTypes in two namespaces - cdf (Locks and Deletes) and cgf (Lines and Points).

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema 
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  elementFormDefault="qualified"
  attributeFormDefault="unqualified" version="1.0">
  <xs:import namespace="http://www.opengis.net/cite/data"
        schemaLocation="http://host/geoserver/wfs/DescribeFeatureType?typeName=cdf:Locks,cdf:Deletes"/>
  <xs:import namespace="http://www.opengis.net/cite/geometry"
        schemaLocation="http://host/geoserver/wfs/DescribeFeatureType?typeName=cgf:Lines,cgf:Points"/>
</xs:schema>

XML/XSD parsers will automatically process a file in this format.