SWECommon CR - Improve Extensibility Mechanisms

Open Geospatial Consortium

Document OGC 08-020
CR-Form-v3

CHANGE REQUEST


SWE Common

CR ?



rev

-

 Current version:

1.0


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Proposed change affects:



AS

Impl Stand X

Best Practices Paper

Title:

 Improve Extensibility Mechanisms

Source:

 Alexandre Robin, Ingo Simonis, Johannes Echterhoff, Michael E. Botts


Work item code: 

Category:

Other

Date:  2008-02-25

 C (Functional modification of feature)
Use one of the following categories:
F (Critical correction)
A (corresponds to a correction in an earlier release)
B (Addition of feature),
C (Functional modification of feature)
D (Editorial modification)

Reason for change:

 Current method for extending SWE Common by deriving new hard typed

structures can break interoperability when using generic software since there
can be ambiguous situations.

Summary of change:  Addition of new DerivableXXX types in the schema forcing the tagging of Data
Components and DataRecord fields with appropriate attributes. This change
is backward compatible.
Consequences if
not approved:

 Without this change the implementation of a generic SWE Common parser is
much harder and will lead to less robust software.

Clauses affected:

 9.2.1 (currently in SensorML 1.0 07-000)

Copyright © 2008 Open Geospatial Consortium, Inc. All Rights Reserved.

1


OGC 08-020

Other specs

 X Other core specifications

Affected:

 SensorML 1.0 - 07-000

Abstract specifications
Best Practices Papers

Supporting Doc.



Other comments:




Status

 NEW

Disposition



Copyright © 2008 Open Geospatial Consortium, Inc. All Rights Reserved.

2

OGC 08-020
Change Request Description
1. Add statement in the specification to force the derivation of new hard typed data
components from specialized schema types (DerivableXXXType), so that derived
objects are appropriately tagged with their base type (i.e. record, array, field…)
2. Several objects in the schema will have to be derived using this mechanism
(SimpleDataRecord, ConditionalValue, ConditionalData, Vector, SquareMAtrix,

etc…)
3. Add examples of derived structures such as geometries. These geometry objects
will be based on ISO 19107.

Copyright © 2008 Open Geospatial Consortium, Inc. All Rights Reserved.

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