EDXL-DE Common Alert Protocol

124 Copyright © 2010 Open Geospatial Consortium, Inc. The relationship between EDXL-DE and CAP is similar to the relationship between SOAP and WFS. Like a WFS message that is embedded within the body of a SOAP message, a CAP message can be the payload within an EDXL-DE message. Because CAP messages already encode routing or targeting information e.g. cap:addresses, cap:area, etc. there is an non-trivial amount of overlap in the kind of information that an EDXL-DE message encodes when compared to the kind of information encoded in a CAP message. Clients considering using CAP as event encoding should therefore clearly identify which information an event needs to contain. If the CAP model provides the properties to encode the required information without at the same time requiring too much additional information that the client does not need, CAP can be used as the event encoding. Otherwise, the development of a more focused encoding is a viable option. Such events can still be inserted into an EDXL-DE container object to leverage routing functionality offered by emergency messaging middleware see section 12.2.9.7. Copyright © 2010 Open Geospatial Consortium, Inc. 125 13 Annex A - Publish Subscribe Requirements This Annex contains the documentation of the requirements that were derived from the abstract publish subscribe model see section 6.2. The requirements are grouped into packages as described in section 6.4. The following subsections first give a graphical overview of the requirements of each package, structured into modules. The requirements with their normative statements are then listed in a table.

13.1.1 Resource Requirements Package

Figure 43: Resource Requirements Table 43: Resource Requirements Details Requirement Number Requirement Normative Statement 004 A resource with lifetime shall provide an operation to explicitly and immediately terminate the resource. 006 A resource with lifetime shall support an operation to renew its termination time to a given time instant. 007 A resource with lifetime shall support the provision of the point in time when the resource will automatically be terminated. 126 Copyright © 2010 Open Geospatial Consortium, Inc. Requirement Number Requirement Normative Statement 008 A resource with lifetime shall support the provision of an endpoint to which a termination event shall be sent when the resource is terminated. 009 A resource with lifetime shall support the automatic termination of itself once the termination time set for the resource is in the past. 060 A resource shall support an explicit or implicit identifier. This can for example be a URL or WS-Addressing endpoint. 061 A resource shall support multiple resource names that can be assigned to it. 062 A resource shall support the inclusion of documentation about the resource. 063 A resource shall support the inclusion of policies that define behavior that is required or requested. 064 A system entity acting as a resource manager shall provide an operation to retrieve one of its resources via its identifier. 067 Before termination of a resource with lifetime, the resource or the entity managing the resource shall publish a termination event to the endpoint provided in the resource.

13.1.2 Consumer Requirements Package

Figure 44: Consumer Requirements