id Standard properties of GML objects .1

Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 31 In addition, the complex type describing the content model of the GML object collection may also include a reference to the attribute group gml:AggregationAttributeGroup to provide additional information about the semantics of the object collection. This information may be used by applications to group GML objects, and optionally to order and index them. attributeGroup name=AggregationAttributeGroup attribute name=aggregationType type=gml:AggregationType attributeGroup The allowed values for the aggregationType attribute are defined by gml:AggregationType. See 8.4 of ISOIEC 11404:1996 for the meaning of the values in the enumeration. simpleType name=AggregationType final=all restriction base=string enumeration value=set enumeration value=bag enumeration value=sequence enumeration value=array enumeration value=record enumeration value=table restriction simpleType NOTE 1 If a collection of aggregation type ―array‖ is implemented in an application schema, then the array type in the application schema needs to model the additional information to cope with indexing. NOTE 2 If a collection of aggregation type ―table‖ is implemented in an application schema, then the table type in the application schema needs to model the additional information to add the required information about the fields and their structure.

7.2.6 Metadata

To associate metadata described by any XML Schema with a GML object, a property element shall be defined whose content model is derived by extension from gml:AbstractMetadataPropertyType. The value of such a property shall be metadata. The content model of such a property type, i.e. the metadata application schema shall be specified by the GML application schema. complexType name=AbstractMetadataPropertyType abstract=true sequence attributeGroup ref=gml:OwnershipAttributeGroup complexType The property type derived from gml:AbstractMetadataPropertyType shall follow one of the patterns specified for GML property types in 7.2.3. By default, this abstract property type does not imply any ownership of the metadata. The owns attribute of gml:OwnershipAttributeGroup may be used on a metadata property element instance to assert ownership of the metadata. If metadata following the conceptual model of ISO 19115 is to be encoded in a GML document, the corresponding Implementation Specification specified in ISOTS 19139 shall be used to encode the metadata information. EXAMPLE 1 Assume that a feature type Road can be associated with two metadata elements, a data quality property horizontalAbsolutAccuracy and a generic ISOTS 19139 metadata property. This may be mapped in the application schema as follows by bundling the metadata properties in a complex property: