#### 8.13.3.3 IfcTable

| Table
| Tabelle

An IfcTable is a data structure for the provision of information in the form of rows and columns. Each instance may have IfcTableColumn instances that define the name, description and units for each column. The rows of information are stored as a list of IfcTableRow objects.

Limitation: For backwards compatibility, the rows of an IfcTable object are constrained to have the same number of cells. The first row of the table provides the number of cells. All other rows are forced to include the same number of cells. This is enforced by the WR2.

Figure 65 illustrates table use.

Figure 65 — Table use

Figure 66 depicts how tables were structured prior to IFC4.

Figure 66 — Table use alternative

> HISTORY New entity in IFC1.5.

> IFC4 CHANGE Columns attribute added.

XSD Specification:

<xs:element name="IfcTable" type="ifc:IfcTable" substitutionGroup="ifc:Entity" nillable="true"/>
<xs:complexType name="IfcTable">
<xs:complexContent>
<xs:extension base="ifc:Entity"/>
</xs:complexContent>
</xs:complexType>

EXPRESS Specification:

ENTITY IfcTable;

Name | : | OPTIONAL IfcLabel;
Rows | : | OPTIONAL LIST [1:?] OF IfcStrippedOptional;
Columns | : | OPTIONAL LIST [1:?] OF IfcTableColumn;

| DERIVE

NumberOfCellsInRow | : | INTEGER := HIINDEX(Rows[1].RowCells);
NumberOfHeadings | : | INTEGER := SIZEOF(QUERY( Temp <* Rows | Temp.IsHeading));
NumberOfDataRows | : | INTEGER := SIZEOF(QUERY( Temp <* Rows | NOT(Temp.IsHeading)));

| WHERE

WR1 | : | SIZEOF(QUERY( Temp <* Rows | HIINDEX(Temp.RowCells) <> HIINDEX(Rows[1].RowCells))) = 0;
WR2 | : | { 0 <= NumberOfHeadings <= 1 };

END_ENTITY;

EXPRESS-G diagram

Attribute Definitions:

Columns | : | The column information associated with this table.
NumberOfCellsInRow | : | The number of cells in each row, this complies to the number of columns in a table. See WR2 that ensures that each row has the same number of cells. The actual value is derived from the first member of the Rows list.
NumberOfHeadings | : | The number of headings in a table. This is restricted by WR3 to max. one.
NumberOfDataRows | : | The number of rows in a table that contains data, i.e. total number of rows minus number of heading rows in table.

Formal Propositions:

WR1 | : | Ensures that each row defines the same number of cells. The rule compares whether all other rows of the IfcTable have the same number of cells as the first row.
WR2 | : | The rule restricts the allowed number of heading rows to no more than one.

Inheritance Graph:

ENTITY IfcTable

| ENTITY IfcTable

Name | : | OPTIONAL IfcLabel;
Rows | : | OPTIONAL LIST [1:?] OF IfcStrippedOptional;
Columns | : | OPTIONAL LIST [1:?] OF IfcTableColumn;

| DERIVE

NumberOfCellsInRow | : | INTEGER := HIINDEX(Rows[1].RowCells);
NumberOfHeadings | : | INTEGER := SIZEOF(QUERY( Temp <* Rows | Temp.IsHeading));
NumberOfDataRows | : | INTEGER := SIZEOF(QUERY( Temp <* Rows | NOT(Temp.IsHeading)));

END_ENTITY;

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