An IfcTableColumn is a data structure that captures column information for use in an IfcTable. Each instance defines the identifier, name, description, and units of measure that are applicable to the columnar data associated with the IfcTableRow objects.
The Identifier identifies the column within the table. If provided, it must be unique within the table. Columns may be cross-referenced across multiple tables by sharing the same column identifier.
The Name is a human-readable caption for the table column. It is not necessarily unique.
The Description provides human-readable text describing the table column.
The Unit indicates the unit of measure to be used for this column's data. If not provided, then project default units are assumed. If ReferencePath is provided, the the unit must be of the same measure as the referenced attribute.
The ReferencePath indicates a relative path to the object and attribute for which data within this column is to be applied.
For constraints, such path is relative to the IfcObjectDefinition associated by IfcRelAssociatesConstraint.RelatedObjects. For a constraint to be satisfied, exactly one row of the table must match the referenced object for all columns where the ReferencePath attribute is set.
ENTITY IfcTableColumn; Identifier : OPTIONAL IfcIdentifier; Name : OPTIONAL IfcLabel; Description : OPTIONAL IfcText; Unit : OPTIONAL IfcUnit; ReferencePath : OPTIONAL IfcReference; END_ENTITY;