IfcTable

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcTable
Name	X	X	MODIFIED	Type changed from STRING to IfcLabel. Instantiation changed to OPTIONAL.
Rows			MODIFIED	Instantiation changed to OPTIONAL.
Columns			ADDED

Semantic definitions at the entity

Entity definition

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 411 illustrates table use.

Figure 411 — Table use

Figure 412 depicts how tables were structured prior to IFC4.

Figure 412 — Table use alternative

HISTORY New entity in IFC1.5.

IFC4 CHANGE Columns attribute added.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
1	Name	IfcLabel	[0:1]		X
2	Rows	IfcTableRow	L[1:?]	Reference to information content of rows.	X
3	Columns	IfcTableColumn	L[1:?]	The column information associated with this table.	X
	NumberOfCellsInRow :=HIINDEX(Rows[1].RowCells)	IfcInteger	[1:1]	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.	X
	NumberOfHeadings :=SIZEOF(QUERY( Temp <* Rows \| Temp.IsHeading))	IfcInteger	[1:1]	The number of headings in a table. This is restricted by WR3 to max. one.	X
	NumberOfDataRows :=SIZEOF(QUERY( Temp <* Rows \| NOT(Temp.IsHeading)))	IfcInteger	[1:1]	The number of rows in a table that contains data, i.e. total number of rows minus number of heading rows in table.	X

Formal Propositions

Rule	Description
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.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcTable
1	Name	IfcLabel	[0:1]		X
2	Rows	IfcTableRow	L[1:?]	Reference to information content of rows.	X
3	Columns	IfcTableColumn	L[1:?]	The column information associated with this table.	X
	NumberOfCellsInRow :=HIINDEX(Rows[1].RowCells)	IfcInteger	[1:1]	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.	X
	NumberOfHeadings :=SIZEOF(QUERY( Temp <* Rows \| Temp.IsHeading))	IfcInteger	[1:1]	The number of headings in a table. This is restricted by WR3 to max. one.	X
	NumberOfDataRows :=SIZEOF(QUERY( Temp <* Rows \| NOT(Temp.IsHeading)))	IfcInteger	[1:1]	The number of rows in a table that contains data, i.e. total number of rows minus number of heading rows in table.	X

Formal representations

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:sequence>

     <xs:element name="Rows" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:sequence>

        <xs:element ref="ifc:IfcTableRow" maxOccurs="unbounded"/>

       </xs:sequence>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcTableRow"/>

       <xs:attribute ref="ifc:cType" fixed="list"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

     <xs:element name="Columns" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:sequence>

        <xs:element ref="ifc:IfcTableColumn" maxOccurs="unbounded"/>

       </xs:sequence>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcTableColumn"/>

       <xs:attribute ref="ifc:cType" fixed="list"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

    <xs:attribute name="Name" type="ifc:IfcLabel" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcTable;

  Name : OPTIONAL IfcLabel;

  Rows : OPTIONAL LIST [1:?] OF IfcTableRow;

  Columns : OPTIONAL LIST [1:?] OF IfcTableColumn;

 DERIVE

  NumberOfCellsInRow : IfcInteger := HIINDEX(Rows[1].RowCells);

  NumberOfHeadings : IfcInteger := SIZEOF(QUERY( Temp <* Rows | Temp.IsHeading));

  NumberOfDataRows : IfcInteger := 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

	Tabelle
	Table
	Table