The SEDRIS Data Representation Model
APPENDIX B - Constraints
Classification Data Constraints

Definition

  1. For a <Union Of Features> instance F:

    1. If F has a directly attached <Classification Data> component, the union_reason of F shall not be SE_UNIONREAS_OTHER.

    2. If F has an inherited <Classification Data> component, the union_reason of F shall not be SE_UNIONREAS_OTHER.

    3. Otherwise, the union_reason of F shall be SE_UNIONREAS_OTHER.

  2. For a <Union Of Geometry> instance G,

    1. If G has a directly attached <Classification Data> component, the union_reason of G shall not be SE_UNIONREAS_OTHER.

    2. If G has an inherited <Classification Data> component, the union_reason of G shall not be SE_UNIONREAS_OTHER.

    3. Otherwise, the union_reason of G shall be SE_UNIONREAS_OTHER.

Rationale

The only permitted cases are those where a <Classification Data> is present to indicate either the SE_UNIONREAS_CLASSIFIED_OBJECT or SE_UNIONREAS_COLLECTION_OF_CLASSIFIED_OBJECTS cases, or where no <Classification Data> is present and the union is there for some non-semantic/non-environmental-object related reason.

Example

  1. Consider a <Union Of Features> instance F that is a component of a <Classification Related Features> instance. The union_reason field value of F cannot be SE_UNIONREAS_OTHER, because F inherits the <Classification Data> link object of its branch.

  2. Consider a <Union Of Geometry Hierarchy> instance UGH with union_reason = SE_UNIONREAS_COLLECTION_OF_CLASSIFIED_OBJECTS, with a <Union Of Primitive Geometry> component UPG. The union_reason field value of UPG cannot be SE_UNIONREAS_OTHER, because UPG inherits the <Classification Data> component of UGH.

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Last updated: July 26, 2006 Copyright © 2006 SEDRIS™