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The SEDRIS Data Representation Model
APPENDIX A - Classes Property Set Index Control Link |
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An instance of this DRM class specifies an <Expression> instance that determines the index field value of all target <Property Set Index> instances, thus controlling which <Property Set> instance is referenced by each such <Property Set Index> instance.
NOTE Since each controlled <Property Set Index> instance may be bound to a different <Property Set Table Group> instance, and thus to a different primary <Property Set Table> instance, the fact that their index values are the same does not mean that the set of <Property Set Index> instances controlled by a given <Property Set Index Control Link> instance reference the same <Property Set> instance.
A tree canopy appears different at different times of the year, with a different colour and texture. This can be achieved by using a different <Property Set> instance for each period of the year. Each <Property Set> instance contains the appropriate <Colour> instance(s) and <Image Mapping Function> instance(s). A <Property Set Index Control Link> instance is used to allow the appropriate <Property Set> instance to be selected.
A <Property Set Index Control Link> instance C controls the value of the index stored in each <Property Set Index> instance that references C.
No. The index always refers to the primary <Property Set Table> component.
No. The link to the <Property Set Table Group> instance is an association within the transmittal, and associations cannot be changed dynamically.
| SE_String | description; | 1 |
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| SE_Integer_Positive | expression_index; | 2 |
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The description field specifies a text description of the purpose of the <Control Link> instance.
The expression_index field specifies the <Expression> component, the value of which controls the index of the affected <Property Set Index> instances.
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