Relationship with ISO 19108 General concepts

Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 149 The ISO 19108 geometry and topology types implemented in GML are specified in ISO 19108; some additional constraints are specified in ISO 19108 for these types, which are also constraints on the temporal geometry and topology components of the GML schema. In addition, GML specifies complementary temporal schema components as described in D.3.11.

14.2 Temporal schema

14.2.1 Abstract temporal objects 14.2.1.1 AbstractTimeObject gml:AbstractTimeObject implements ISO 19108 TM_Object see D.2.5.2 and ISO 19108:2002, 5.2.2 and acts as the head of a substitution group for all temporal primitives and complexes. It is declared as follows: element name=AbstractTimeObject type=gml:AbstractTimeObjectType abstract=true substitutionGroup=gml:AbstractGML A gml:AbstractTimeObject may be used in any position that a gml:AbstractGML is valid. Its content model is defined as follows: complexType name=AbstractTimeObjectType abstract=true complexContent extension base=gml:AbstractGMLType complexContent complexType NOTE The content model of gml:AbstractTimeObject is a vacuous extension of AbstractGMLType. Types derived from this have the standard GML object properties available: abstractMetadataProperty, description, descriptionReference, name.

14.2.1.2 AbstractTimePrimitive

gml:AbstractTimePrimitive implements ISO 19108 TM_Primitive see D.2.5.2 and ISO 19108:2002, 5.2.3 and acts as the head of a substitution group for geometric and topological temporal primitives. It is declared as follows: element name=AbstractTimePrimitive type=gml:AbstractTimePrimitiveType abstract=true substitutionGroup=gml:AbstractTimeObject A gml:AbstractTimePrimitive may be used in any position that a gml:AbstractTimeObject is valid. Its content model is defined as follows: complexType name=AbstractTimePrimitiveType abstract=true complexContent extension base=gml:AbstractTimeObjectType sequence element name=relatedTime type=gml:RelatedTimeType minOccurs=0 maxOccurs=unbounded sequence extension complexContent complexType This extends the model for generic temporal objects with properties indicating relationships between this temporal primitive and other temporal primitives. The definition of gml:RelatedTimeType is provided in 14.2.1.4. 150 Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved.

14.2.1.3 TimePrimitivePropertyType, validTime

gml:TimePrimitivePropertyType provides a standard content model for associations between an arbitrary member of the substitution group whose head is gml:AbstractTimePrimitive and another object: complexType name=TimePrimitivePropertyType sequence minOccurs=0 element ref=gml:AbstractTimePrimitive sequence attributeGroup ref=gml:AssociationAttributeGroup attributeGroup ref=gml:OwnershipAttributeGroup complexType gml:validTime is a convenience property element declared as follows: element name=validTime type=gml:TimePrimitivePropertyType

14.2.1.4 RelatedTimeType

gml:RelatedTimeType provides a content model for indicating the relative position of an arbitrary member of the substitution group whose head is gml:AbstractTimePrimitive. It extends the generic gml:TimePrimitivePropertyType with an XML attribute relativePosition, whose value is selected from the set of 13 temporal relationships identified by Allen 1983: complexType name=RelatedTimeType complexContent extension base=gml:TimePrimitivePropertyType attribute name=relativePosition simpleType restriction base=string enumeration value=Before enumeration value=After enumeration value=Begins enumeration value=Ends enumeration value=During enumeration value=Equals enumeration value=Contains enumeration value=Overlaps enumeration value=Meets enumeration value=OverlappedBy enumeration value=MetBy enumeration value=BegunBy enumeration value=EndedBy restriction simpleType attribute extension complexContent complexType

14.2.1.5 AbstractTimeComplex

gml:AbstractTimeComplex is a collection of temporal primitives and implements ISO 19108 TM_Complex see D.2.5.2 and ISO 19108:2002, 5.2.2 and acts as the head of a substitution group for temporal complexes. It is declared as follows: element name=AbstractTimeComplex type=gml:AbstractTimeComplexType abstract=true substitutionGroup=gml:AbstractTimeObject