Class Name: DRM Class Summary Item

Superclass - <Base Summary Item>

Subclasses

Definition

An instance of this DRM class is used as part of a summary of the content of a transmittal to indicate that at least one instance of the DRM class specified exists in that transmittal. <DRM Class Summary Item> instances are combined together to form a list of the classes that are present in a transmittal or part of a transmittal. Each such list has only one entry per class. However, it does not have to be a complete list of every class used, and it can include abstract classes.

Each <DRM Class Summary Item> instance can optionally have a list of <EDCS Use Summary Item> components giving the classifications that are attached to instances of the given class in the transmittal. This only may exist for those classes that can have classification information.

Each <DRM Class Summary Item> instance can also have a list of <SRF Summary> components giving the SRFs defined in the transmittal by instances of that class. This only may exist for those classes that contain SRF context information.

Primary Page in DRM Diagram:

• 20

Secondary Pages in DRM Diagram:

Example

1. A summary of the classes used in an entire transmittal, as depicted in Figure 6.12

   

   Figure 12 — <DRM DRM Class Summary Item> entire transmittal summary example

2. A summary of classes used in part of a transmittal.

   Assume that the geometry portion of the given <Environment Root> instance has the layout depicted in Figure 6.13.

   

   Figure 13 — <DRM DRM Class Summary Item> transmittal portion summary example

   The geometry portion of the given <Environment Root> instance is therefore summarized as depicted in Figure 6.14.

   

   Figure 14 — <DRM DRM Class Summary Item> geometry portion example

FAQs

Why is the <Union Of Primitive Geometry> instance in Example #2 a <DRM Class Summary Item> instance rather than a <Hierarchy Summary Item> instance?

This illustrates the possible use of a <DRM Class Summary Item> instance if we were to use a <Hierarchy Summary Item> instance to show only the top level hierarchy (for some reason).

The data producer may decide, for a number of reasons, that it would be useful to summarize the hierarchy down to a certain level only, but that it is also useful to show that there are aggregates such as <Union Of Primitive Geometry> instances below that level - i.e., showing that they exist, rather than showing their position in the hierarchy, is what is of value.

Hey! The examples for <DRM Class Summary Item> show <Polygon> instances and <Vertex> instances as <DRM Class Summary Item> instances, but the examples for <Primitive Summary Item> show them as <Primitive Summary Item> instances! Why isn't this ambiguous?

This isn't ambiguous because the two classes (<DRM Class Summary Item> and <Primitive Summary Item>) summarize different aspects of a transmittal. Therefore the same classes can (and will) quite legitimately be represented by both. So <Polygon> instances and <Vertex> instances can be described by <DRM Class Summary Item> instances, to summarize their presence in the transmittal, and as <Primitive Summary Item> instances, to show common patterns of DRM objects in which they are used.

Constraints

• <<Publishable Object>>

Composed of (two-way metadata) (inherited)

• zero or more <EDCS Use Summary Item> instances¹

Composed of (two-way metadata)

• zero or more <SRF Summary> instances

Component of (two-way)

• zero or more <Hierarchy Summary Item> instances²
• zero or one <Transmittal Summary> instance³

Inherited Field Elements

Notes

Composed of Notes

EDCS_Use_Summary_Item

Component of Notes

Hierarchy_Summary_Item

Transmittal_Summary

Fields Notes

drm_class

The drm_class field indicates the DRM class of the DRM object(s) represented by the <Base Summary Item> instance.