Table 6.132—DRM_Hierarchy_Summary_Item
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Property |
Description |
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Superclass |
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Class |
· <DRM Hierarchy Summary Item> |
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Subclass |
· none |
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Definition |
An object of this DRM class is used as part of a summary of the hierarchical structure beneath <DRM Environment Root> or within a <DRM Model>. A <DRM Hierarchy Summary Item> represents an instance, or number of identical instances, of a class that exists within the <DRM Model> or under <DRM Environment Root>. <DRM Hierarchy Summary Item>s can only represent objects of the <DRM Geometry Hierarchy> and <DRM Feature Hierarchy> types and subtypes. They are combined together to form a hierarchy that mirrors the hierarchy of the objects that the <DRM Hierarchy Summary Item>s represent. This summary is actually a compressed form of the real hierarchy, as each <DRM Hierarchy Summary Item> may represent a number of instances of that object type. <DRM Hierarchy Summary Item> therefore has a multiplicity field, recording how many of the object type it actually represents. Note that all instances represented by one <DRM Hierarchy Summary Item> shall have exactly the same hierarchical pattern beneath them, right down to where the hierarchy summary finishes. In essence, the <DRM Hierarchy Summary Item> actually represents both the object instance and the specific hierarchy of objects underneath it. Each <DRM Hierarchy Summary Item> can have an optional association to the <DRM Geometry Hierarchy>(s) or <DRM Feature Hierarchy>(s) that it summarizes. Each <DRM Hierarchy Summary Item> (i.e. each object type) can optionally have a list of <DRM EDCS Use Summary Item>s giving the classifications that are attached to those instances in the transmittal. The hierarchy Summary does not have to be a total representation of the entire transmittal hierarchy and can be limited to a useful high level summary. If the producer of the transmittal deems it of potential use to consumers, the branches of the Hierarchy Summary can terminate with a list of <DRM DRM Class Summary Item>s representing the objects beneath that point in the hierarchy. |
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Example(s) |
· Consider an <DRM Environment Root> instance for which the geometry is to be summarized.
The geometry portion of the above <DRM Environment Root> can therefore summarized as follows. Note that this is the same <DRM Environment Root> instance as shown above, but for readability only the <DRM Hierarchy Summary Item> portion of its instance diagram is shown here.
The <DRM Hierarchy Summary Item> tree, rooted at the <DRM Environment Root>, parallels the structure of the corresponding geometry. In this instance, the data provider has elected not to provide a detailed summary of the <DRM Union Of Geometry Hierarchy>'s structure. The list of <DRM DRM Class Summary Item> components merely identify classes that are somewhere below the <DRM Union Of Geometry Hierarchy>, rather than the patterns in which they appear. The <DRM EDCS Use Summary Item> components summarize patterns of EDCS Classification Codes, possibly used together with EDCS Attribute Codes, in the context being summarized. If the data provider wished to summarize the hierarchy of the <DRM Union Of Geometry Hierarchy> in detail, its <DRM Hierarchy Summary Item> could be provided with appropriate <DRM Hierarchy Summary Item> components as desired, until the summary reached the level of <DRM Primitive Geometry> and the hierarchy summary came to an end. For examples of summaries of <DRM Primitive Geometry> patterns, see <DRM Primitive Geometry>. |
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Inherited field elements |
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Field elements |
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Associated to (one-way) (inherited) |
· none |
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Associated to (one-way) |
· zero or more <DRM Feature Hierarchy>s · zero or more <DRM Geometry Hierarchy>s |
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Associated by (one-way) (inherited) |
· none |
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Associated by (one-way) |
· none |
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Associated with (two-way) (inherited) |
· none |
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Associated with (two-way) |
· none |
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Composed of (two-way) (inherited) |
· none |
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Composed of (two-way) |
· zero or more <DRM DRM Class Summary Item>s4 · zero or more <DRM Hierarchy Summary Item>s |
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Composed of (two-way metadata) (inherited) |
· zero or more <DRM EDCS Use Summary Item>s5 |
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Composed of (two-way metadata) |
· none |
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Component of (two-way) (inherited) |
· none |
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Component of (two-way) |
· zero or more <DRM Environment Root>s4 · zero or more <DRM Hierarchy Summary Item>s · zero or one <DRM Model> |
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Constraints |
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Notes |
1 The DRM class of the object represented by the summary item. 2 Specifies the meaning of the multiplicity field. 3 The number of identical instances represented, or the order of magnitude of that number. If the multiplicity is unknown, the multiplicity shall be set to zero. 4 Represents a list of classes that occur beneath this point in the component tree. 5 Summarizes EDCS usage by instances of the specified class that occur somewhere in the scope being summarized. |
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Class diagram |
