Defined in File Ifc2x3.h
IfcClassification: public IfcUtil::IfcBaseEntity¶
An IfcClassification is used for the arrangement of objects into a class or category according to a common purpose or their possession of common characteristics. A classification in the sense of IfcClassification is taxonomy, or taxonomic scheme, arranged in a hierarchical structure. A category of objects relates to other categories in a generalization-specialization relationship. Therefore the classification items in an classification are organized in a tree structure.
HISTORY New class in IFC Release 1.5. Modified in IFC 2x.
IFC 2x4 CHANGE Attribute Edition made optional. Attributes: PublicationLocation, Description and ReferenceTokens added. Inverse attribute HasClassificationReferences added.
Classification use definitions IfcClassification identifies the classification system or source from which a classification notation is derived. Each classification reference or classification item, belonging to a single classification system, shall reference a single instance of IfcClassification. Therefore, each particular classification system or source used should have only one IfcClassification instance. However, because multiple classification is allowed, there may be many IfcClassification objects used, each identifying a different classification system or source.
A classification system declared may be either formally published (such as Omniclass, Uniclass, Masterformat, or DIN) or it may be a locally defined method of classifiying information. There are two methods to define a classification system within an IFC dataset:
Including the classification system structure within the dataset: Here a hierarchical tree of IfcClassificationItem’s is included that defines the classification system including the relationship between the classification items. An IfcClassificationNotation is used to classify an object. Referencing the classification system by a classification key or id: Here the IfcClassificationReference is used to assign a classification id or key to each classified object.
Source (or publisher) for this classification.
NOTE that the source of the classification means the person or organization that was the original author or the person or organization currently acting as the publisher.
The edition or version of the classification system from which the classification notation is derived.
NOTE the version labeling system is specific to the classification system.
IFC2x4 CHANGE The attribute has been changed to be optional.
Whether the optional attribute EditionDate is defined for this IfcClassification.
The date on which the edition of the classification used became valid.
NOTE The indication of edition may be sufficient to identify the classification source uniquely but the edition date is provided as an optional attribute to enable more precise identification where required.
IFC2x4 CHANGE The data type has been changed to IfcDate, the date string according to ISO8601.
The name or label by which the classification used is normally known.
NOTE Examples of names include CI/SfB, Masterformat, BSAB, Uniclass, STABU, DIN276, DIN277 etc.