|Définition de propriété|
|Merkmal - Definition|
IfcPropertyDefinition defines the generalization of
all characteristics (i.e. a grouping of individual properties),
that may be assigned to objects. Currently, subtypes of
IfcPropertyDefinition include property set occurrences,
property set templates, and property templates.
Property set template -
IfcPropertySetTemplate, a collection of property templates
that determine the definition of properties used within a project
Property template -
IfcPropertyTemplate, a single template that determines the
definition of a particular property used in the same project
context. The template may determine the name, description, data
type, the unit, or a standard expression for each property that is
based on that template.
Property set occurrence -
IfcPropertySet, a set of individual properties (that may
or may not be determined by a property template) holding individual
values, measure types and units, and are associated to an object
occurrence or object type.
NOTE The subtype hierarchy of IfcPropertyDefinition also includes statically defined property sets as IfcPreDefinedPropertySet. Those are rarely used collections of fixed attributes combined in an entity definition. The IfcPreDefinedPropertySet can not be determined by an IfcPropertySetTemplate.
NOTE Individual properties, (subtypes of IfcProperty), are currently not included in the subtype hierarchy of IfcPropertyDefinition. This anomaly is due to upward compatibility reasons with earlier releases of this
HISTORY New entity in IFC2.0
Relationship use definition
Property definitions define information that is shared among
multiple instances of objects, either object occurrences or object
types. IfcPropertyDefinition's (by their instantiable
subtypes) can participated within the following relationships:
- Assignment to a project context - an
HasContext relationship to IfcRelDeclares that
establishes the project context in which this property definition
is declared. This relationship is predominately applicable to
subtypes of IfcPropertyTemplateDefinition.
- Association to external resources - an
HasAssociation relationship to IfcRelAssociates
that refers to external sources of information (most notably a
classification or document) and creates a uni-directional
association. There is no dependency implied by the
Subtypes are included in more specific relationships, see
IfcPropertyTemplateDefinition for details.
XSD Specification: <xs:element name="IfcPropertyDefinition" type="ifc:IfcPropertyDefinition" abstract="true" substitutionGroup="ifc:IfcRoot" nillable="true"/>
<xs:complexType name="IfcPropertyDefinition" abstract="true">
|HasAssociations|| : ||Reference to the relationship IfcRelAssociates and thus to those externally defined concepts, like classifications, documents, or library information, which are associated to the property definition.|
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