SWE Common Data Model OGC 08-094r1
Requirement
http:www.opengis.netspecSWE2.0reqxsd-simple-componentsextension-namespace-unique
Req 60. All extensions of the XML schemas described in this standard shall be
defined in a new unique namespace.
Extensions are not allowed to change the meaning or behavior of elements and types defined by this standard in any way in this case, new classes or properties shall me
defined. This guarantees that implementations that have no knowledge of an extension can still properly use XML instances containing these extensions.
Requirement
http:www.opengis.netspecSWE2.0reqxsd-simple-componentsextension-coherent-with-core
Req 61. Extensions of this standard shall not redefine or change the meaning or
behavior of XML elements and types defined in this standard.
8.1.2 Base Abstract Complex Types
Several base abstract types are defined in the “basic_types.xsd” schema file. They are used as base substitution groups for all global XML elements defined in this standard.
Below are XML schema snippet for the “AbstractSWE”, “AbstractSWEIdentifiable” and “AbstractSWEValue” elements and corresponding complex types:
element name
= AbstractSWE
abstract =
true type
= swe:AbstractSWEType
complexType name
= AbstractSWEType
sequence element
name =
extension type
= anyType
minOccurs =
maxOccurs =
unbounded sequence
attribute name
= id
use =
optional complexType
The “AbstractSWE” complex type is the base for all derived complex types defined in this standard. It defines a first extension mechanism as an optional “extension” element
that allows for any extended element content in a namespace other than the SWE Common Data Model namespace. It also has an optional “id” attribute allowing
referencing the object that derives from it.
element name
= AbstractSWEIdentifiable
abstract =
true substitutionGroup
= swe:AbstractSWE
type =
swe:AbstractSWEIdentifiableType complexType
name =
AbstractSWEIdentifiableType complexContent
extension base
= swe:AbstractSWEType
sequence element
name =
identifier type
= anyURI
minOccurs =
element name
= label
type =
string minOccurs
= element
name =
description type
= string
minOccurs =
sequence extension
Copyright © 2011 Open Geospatial Consortium
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OGC 08-094r1 SWE Common Data Model
complexContent complexType
The “AbstractSWEIdentifiable” complex type derives from “AbstractSWE” and adds three identification elements. These elements are to be used as described in the UML
section of this standard.
The following XML elements and complex types are defined in the “simple_components.xsd” schema file:
element name
= AbstractDataComponent
abstract =
true type
= swe:AbstractDataComponentType
substitutionGroup =
swe:AbstractSWEIdentifiable complexType
name =
AbstractDataComponentType abstract
= true
complexContent extension
base =
swe:AbstractSWEIdentifiableType attribute
name =
definition type
= anyURI
use =
required attribute
name =
updatable type
= boolean
use =
optional attribute
name =
optional type
= boolean
use =
optional default
=fals e
extension complexContent
complexType
The “AbstractDataComponent” complex type adds XML attributes as defined in the UML class with the same name. The meaning of the corresponding UML class attributes
is detailed in clause 7.2.2.
Requirement
http:www.opengis.netspecSWE2.0reqxsd-simple-componentsdefinition-resolvable
Req 62. The “definition” attribute shall contain a URI that can be resolved to the
complete human readable definition of the property that is represented by the data
component.
element name
= AbstractSimpleComponent
abstract =
true substitutionGroup
= swe:AbstractDataComponent
type =
swe:AbstractSimpleComponentType complexType
name =
AbstractSimpleComponentType abstract
= true
complexContent extension
base =
swe:AbstractDataComponentType sequence
element name
= quality
type =
swe:QualityPropertyType minOccurs
= maxOccurs
= unbounded
element name
= nilValues
type =
swe:NilValuesPropertyType minOccurs
= sequence
attribute name
= referenceFrame
type =
anyURI use
= optional
attribute name
= axisID
type =
string use
= optional
extension complexContent
complexType
The “AbstractSimpleComponent” complex type adds XML attributes as defined in the UML class with the same name. The meaning of the corresponding UML properties is
detailed in clause 7.2.3. The “definition” attribute is mandatory on all elements derived
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