Class Name: Attribute Set

Superclass - SEDRIS Abstract Base

Definition

An Attribute Set can be used to group together sets of objects that are components of Geometry or Feature and which specify attributes (e.g. Rendering Properties, Rendering Priority Level) or metadata. This allows these sets of objects to be reused by a number of Geometries or Features.

Primary Page in DRM Diagram:

• 19

Secondary Pages in DRM Diagram:

• 10

Example

1. A number of polygons that are all colored red and rendered using flat shading could each contain the same Attribute Set. This Attribute Set would contain a Color object specifying red and a Rendering Properties object specifying a flat shading type.
2. A number of polygons that are all colored green, have grass texture that is modulated and have a Grass/Thatch Surface Material Code. A common Attribute Set would contain a Color object specifying green, an Image Mapping Function object specifying a Modulate mapping method and a Property Value object specifying an EDCS_AC_SURFACE_MATERIAL_CATEGORY value of SE_PROP_VAL_SMC__GRASS_OR_THATCH.
3. A number of polygons that all have the same electromagnetic properties and are colored grey. A common Attribute Set would contain a Color object specifying grey and a Property Table Reference into a Property Table of electromagnetic properties.
4. A Feature has an association with a Geometry that has been developed from it. Both reference the same Attribute Set that contains a Color object, Image Mapping Function and Browse Graphic. The Feature would use the Color and Browse Graphic objects but would ignore the Image Mapping Function. The Geometry would use the Color and Image Mapping Function but ignore the Browse Graphic.
5. A Feature contains a Data Quality with fictional set to true. It also references an Attribute Set that contains a Data Quality object with fictional set to false. As a Feature may only contain one Data Quality object, the Data Quality object with fictional set to true would be used as it is contained directly by the Feature.
6. A Geometry contains two Property Table References and references an Attribute Set that contains another three. As a Geometry may contain many Property Table Reference objects, all five would be used by the Geometry as required. The two that are contained directly would be used first and then the three that are contained in the Attribute Set.
7. A Geometry contains two Image Mapping Functions and references an Attribute Set that contains another two. As a Geometry may contain many ordered Image Mapping Function objects, all four would be used by the Geometry as required. The two that are contained directly would be used in order first and then the three that are contained in the Attribute Set, again in order.
8. A Geometry contains two Property Table References and references two Attribute Sets. The first Attribute Set contains another Property Table Reference and the second Attribute Set contains another three Property Table References. As a Geometry may contain many Property Table Reference objects, all six would be used by the Geometry as required. The two that are contained directly would be used first, then the one that is contained in the first Attribute Set and finally the three that are contained in the second Attribute Set.

FAQs

What is the order of precedence for attribute objects?

Geometry or Feature may contain a number of attribute and/or meta data objects as well as a reference to an Attribute Set. If there is a conflict between the two, then the objects contained directly in the Geometry or Feature will have precedence over those in the Attribute Set. This precedence will behave differently depending on the numeration of the relationship that the attribute or metadata object in question has with the containing Geometry or Feature. In the event of a clash, the following rules will apply based on this numeration:

• Zero or one:
  The object contained directly by the Geometry or Feature is used.
• Zero or more:
  Those contained directly by the Geometry or Feature are used, followed by those contained in the Attribute Set, if required.
• Zero or more {ordered}:
  Those contained directly by the Geometry or Feature are used in order, followed by those contained in the Attribute Set, in order, as required.

What if a Geometry or Feature contains references to more than one Attribute Set and there is a clash between the attribute objects they contain?

Geometry and Features may contain an ordered list of Attribute Set Index objects. In the case of a clash, attribute objects contained in Attribute Set referenced first in this ordered list have precedence over those contained in Attribute Set that are referenced later. Precedence in this case behaves according to the same rules that define precedence between Geometry/Features and Attribute Set (see above).

What if an Attribute Set contains attribute objects that are related to Features but is referenced by a Geometry class? Or vice versa?

Any attribute classes in an Attribute Set that have no meaning to the object that references the Attribute Set will be ignored.

Constraints

• Attribute Set Components
• No Attribute Conflicts

Composed of (one-way)

• optionally, a Classification Data
• optionally, some Colors
• optionally, some {ordered} Image Mapping Functions
• optionally, a Light Rendering Properties
• optionally, some Property Tables
• optionally, some Property Table References
• optionally, some Property Values
• optionally, a Rendering Priority Level
• optionally, a Rendering Properties
• optionally, a Spatial Domain

Composed of (one-way metadata)

• optionally, an Access
• optionally, some Browse Graphics
• optionally, a Citation
• optionally, some Cross References
• optionally, a Data Quality
• optionally, a Description
• optionally, a Keywords
• optionally, a Point of Contact
• optionally, a Time Constraints Data

Component of (one-way)

• one Attribute Set Table