Supported GML Versions

GML 3.1.1

  • GML 3.1.1 application schemas are supported for WFS 1.1.0.

  • Clients must specify WFS 1.1.0 in requests because the GeoServer default is WFS 2.0.0.

  • GET URLs must contain version=1.1.0 to set the WFS version to 1.1.0.

GML 3.2.1

  • GML 3.2.1 application schemas are supported for WFS 1.1.0 and (incomplete) WFS 2.0.0.

  • Some WFS 2.0.0 features not in WFS 1.1.0 such as GetFeatureById are not yet supported.

  • Clients using WFS 1.1.0 must specify WFS 1.1.0 in requests and select the gml32 output format for GML 3.2.1.

  • To use WFS 1.1.0 for GML 3.2.1, GET URLs must contain version=1.1.0 to set the WFS version to 1.1.0 and outputFormat=gml32 to set the output format to GML 3.2.1.

  • The default WFS version is 2.0.0, for which the default output format is GML 3.2.1.

  • All GML 3.2.1 responses are contained in a WFS 2.0.0 FeatureCollection element, even for WFS 1.1.0 requests, because a WFS 1.1.0 FeatureCollection cannot contain GML 3.2.1 features.

Secondary namespace for GML 3.2.1 required

GML 3.2.1 WFS responses are delivered in a WFS 2.0.0 FeatureCollection. Unlike WFS 1.1.0, WFS 2.0.0 does not depend explicitly on any GML version. As a consequence, the GML namespace is secondary and must be defined explicitly as a secondary namespace. See Secondary Namespaces for details.

For example, to use the prefix gml for GML 3.2, create workspaces/gml/namespace.xml containing:


and workspaces/gml/workspace.xml containing:


Failure to define the gml namespace prefix with a secondary namespace will result in errors like: The prefix "null" for element "null:name" is not bound.

while encoding a response (in this case one containing gml:name), even if the namespace prefix is defined in the mapping file.

GML 3.2.1 geometries require gml:id

GML 3.2.1 requires that all geometries have a gml:id. While GeoServer will happily encode WFS responses without gml:id on geometries, these will be schema-invalid. Encoding a gml:id on a geometry can be achieved by setting an idExpression in the mapping for the geometry property. For example, gsml:shape is a geometry property and its gml:id might be generated with:

        <OCQL>strConcat('shape.', getId())</OCQL>

In this example, getId() returns the gml:id of the containing feature, so each geometry will have a unique gml:id formed by appending the gml:id of the containing feature to the string "shape.".

If a multigeometry (such as a MultiPoint or MultiSurface) is assigned a gml:id of (for example) parentid, to permit GML 3.2.1 schema-validity, each geometry that the multigeometry contains will be automatically assigned a gml:id of the form parentid.1, parentid.2, … in order.

GML 3.3

The proposed GML 3.3 is itself a GML 3.2.1 application schema; preliminary testing with drafts of GML 3.3 indicates that it works with app-schema as expected.