OGC GML Format Attributes (Feature Representation)

In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Type Attributes), this format also adds format-specific attributes (Format Attributes).

The xml_type attribute identifies the FME GML geometry. The valid values for this attribute are:

xml_type

Geometry

Description

xml_arc

Arc

Features having their xml_type set to xml_arc are circular arc segments.

xml_area

Area

Features having their xml_type set to xml_area are either a single closed polyline feature (simple closed polygon), a donut, or an aggregate of donuts (and/or simple polygons). A simple closed polygon contains at least four coordinates, with the first and last coordinate being equal.

xml_line

Line

Features having their xml_type set to xml_line are polyline features and have at least two coordinates.

xml_no_geom

No Geometry

Features having their xml_type attribute set to xml_no_geom do not contain any geometry data.

xml_point

Point

Features having their xml_type set to xml_point are single coordinate features.

Other attributes, including the feature’s feature type, are dependent on the GML application schema.

It is possible to control the name and position for the GML geometry properties for a GML feature type. See Geometry attributes for details.

GML Format Attributes

Attribute Name

Contents

gml_id

The unique identifier for each feature. This attribute must be unique in the dataset scope.

gml_original_coordinate_system

The original value for the srsName attribute in the GML geometry. For example,

srsName="urn:ogc:def:crs:EPSG::4326"

gml_parent_id

The unique identifier representing the feature’s parent in the hierarchy. This must reference another feature in the dataset.

gml_parent_property

In the GML dataset hierarchy, a child feature type is a value of a parent's feature type property. For example, in AIXM5, the gml_parent_property for the AirspaceTimeSlice feature is set to "timeSlice":

<aixm:Airspace gml:id="....">
    ....
    <aixm:timeSlice>
      <aixm:AirspaceTimeSlice gml:id="....">
    ....
    </aixm:timeSlice>
</aixm:Airspace>

gml_srsName

This attribute can overwrite the CRS value that is written in the GML instance’s srsName attributes.

By default, the FME coordinate system name in a feature is transferred directly onto the srsName attribute. This attribute allows you to provide your own URN CRS string for the srsName attributes.