|
The SEDRIS Data Representation Model
APPENDIX A - Classes Geometry ID Control Link |
|---|
The specialized <Control Link> used to provide the connection between an ordered aggregation of <Expressions> and the target fields of a <Geometry ID>.
The expr_index field is a 1-based index into the ordered aggregation of <Expressions>, and is used to select the specific <Expression> that controls the value of <Geometry ID>'s ID field.
Consider a <Geometry Model> containing a <Geometry Node>, which has a <Geometry ID> component. In this case, the data provider wishes to ensure that each <Geometry Model Instance> uses a unique <Geometry ID> for this node.
In order to do this, the data provider attaches a <Geometry ID Control Link> to the <Geometry ID> instance, where the ID field's controlling <Expression> is a <Variable>. In this way, each <Geometry Model Instance> can supply a different <Literal> <Expression> to be plugged into the <Geometry ID Control Link>'s <Variable>, so that each <Geometry Model Instance> provides a different ID for the <Geometry Node> within the <Model>.
No FAQs supplied.
| SE_String | description; | (notes) |
|---|
| SE_Integer_Positive | expr_index; | (notes) |
|---|
This is a text description of the given <Control Link> instance's purpose.
This specifies which component <Expression> controls the ID of the affected <Geometry ID> instances.
|