008]. The mandatory values of various XML attributes shall be as specified in Table 6. Similarly, the optional attribute values listed in Error Reference source not found.
shall be included or not depending on whether that operation is implemented by that server. In Table 6 and Error Reference source not found., the “Attribute name”
column uses dot-separator notation to identify parts of a parent item. The “Attribute value” column references an operation parameter, in this case an operation name, and the
meaning of including that value is listed in the right column.
Table 6 — Required values of OperationsMetadata section attributes
Attribute name Attribute value
Meaning of attribute value
GetCapabilities The operation is implemented by
this server.
Advertise
The operation is implemented by this server.
CancelAdvertisement
The operation is implemented by this server.
RenewAdvertisement
The operation is implemented by this server.
Subscribe
The operation is implemented by this server.
CancelSubscription
The operation is implemented by this server.
RenewSubscription
The operation is implemented by this server.
Operation.name
10.3.3 Contents section
The Contents section of a service metadata document contains metadata about the data served by this server. For the SAS, this Contents section shall contain data about
subscription options: The SAS interface allows clients to subscribe to alerts or to publish alerts. The two necessary sections provide all information a client needs to perform its
intended task.
In case a client wants to advertise new publications, all it has to check is if the SAS instance accepts advertisements. This is indicated by the
AcceptAdvertisements
elements. The only possible values are true and false. In case the SAS accepts advertisements, the next step would be to send an advertise request.
In case that a client wants to subscribe to alerts, the
SubscriptionOffering
Element contains all information how the final at the messaging server subscription has to be
performed. Multiple
SubcriptionOffering
elements are pooled in a
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Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved.
SubscriptionOfferingList
. The following figure shows the structure of the Contents element.
Figure 11: Contents element in XMLSpy notation
The
SubscriptionOffering
is shown in the following figures in UML and XMLSpy notation.
Figure 12: SubscriptionOffering element in UML notation
Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved.
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Figure 13: SubscriptionOffering in XMLSpy notation 10.3.4 Capabilities document XML encoding
A XML schema fragment for a SAS service metadata document extends ows:CapabilitiesBaseType in owsCommon.xsd of [OGC 05-008], and can be found in
annex B sasGetCapabilities.xsd.
10.3.5 Capabilities document example
In response to GetCapabilities operation request, a SAS server might generate a document that looks like See Annex D1 for an entire capabilities document:
Example will follow
24
Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved.
10.3.6 Exceptions
When a SAS server encounters an error while performing a GetCapabilities operation, it shall return an exception report message as specified in Clause 8 of [OGC 05-008]. The
allowed exception codes shall include those listed in Table 5 of Subclause 7.4.1 of [OGC 05-008], if the updateSequence parameter is implemented by the server.
11 Advertise operation mandatory
11.1 Introduction