4.1.2.2 Classification Association
The concept Classification Association describes how objects and object types can be further described by associating references to external sources of information. The source of information can be:
a classification system;
a dictionary server;
any external catalogue that classifies the object further;
any service that combines the above features.
An individual item within the external source of information can be selected. It then applies the inherent meaning of the item to the IfcObject or IfcTypeObject .
NOTE The classification system or dictionary server that is used within the project itself can also be indicated at the level of IfcProject or IfcProjectLibrary either as an external source, or copied with all relevant classification items into the project data. Use the concept Project Classification Information to utilize this functionality.
The main attributes to be provided for a Classification Association are:
Identification : holds the key provided for a specific reference to classification items (or tables)
Name : allows for a human interpretable designation of a classification notation
The following diagram shows the generic classes and relationships used when applying this concept.
In addition, concepts may have particular importance to common or standardised industry practices and scenarios. For these specific usage scenarios, the table below shows a recommended list of general usage patterns that users may adopt.
G
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcObjectDefinition.htm'>IfcObjectDefinition</a>
IfcObjectDefinition
1. GlobalId
[1:1]
2. OwnerHistory
[0:1]
3. Name
[0:1]
4. Description
[0:1]
HasAssignments
[0:?]
Nests
[0:1]
IsNestedBy
[0:?]
HasContext
[0:1]
IsDecomposedBy
[0:?]
Decomposes
[0:1]
HasAssociations
[0:?]
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcRelAssociatesClassification.htm'>IfcRelAssociatesClassification</a>
IfcRelAssociatesClassification
1. GlobalId
[1:1]
2. OwnerHistory
[0:1]
3. Name
[0:1]
4. Description
[0:1]
5. RelatedObjects
[1:?]
6. RelatingClassification
[1:1]
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcObjectDefinition.htm'>IfcObjectDefinition</a>:HasAssociations1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcRelAssociatesClassification.htm'>IfcRelAssociatesClassification</a>:RelatedObjects0
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>
IfcClassificationReference
1. Location
[0:1]
Identification
2. Identification
[0:1]
Name
3. Name
[0:1]
ExternalReferenceForResources
[0:?]
4. ReferencedSource
[0:1]
5. Description
[0:1]
6. Sort
[0:1]
ClassificationRefForObjects
[0:?]
HasReferences
[0:?]
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcRelAssociatesClassification.htm'>IfcRelAssociatesClassification</a>:RelatingClassification1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>:IfcClassificationReference0
IfcIdentifier_0
IfcIdentifier
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>:Identification1->IfcIdentifier_0:IfcIdentifier0
IfcLabel_0
IfcLabel
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>:Name1->IfcLabel_0:IfcLabel0
IfcText_0
IfcText
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>:Description1->IfcText_0:IfcText0
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>
IfcClassification
ClassificationSource
1. Source
[0:1]
2. Edition
[0:1]
3. EditionDate
[0:1]
ClassificationName
4. Name
[1:1]
5. Description
[0:1]
6. Specification
[0:1]
ClassificationTokens
7. ReferenceTokens
[1:?]
ClassificationForObjects
[0:?]
HasReferences
[0:?]
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>:ReferencedSource1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:IfcClassification0
IfcIdentifier_2
IfcIdentifier
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>:Sort1->IfcIdentifier_2:IfcIdentifier0
IfcURIReference_1
IfcURIReference
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassificationReference.htm'>IfcClassificationReference</a>:Location1->IfcURIReference_1:IfcURIReference0
IfcLabel_1
IfcLabel
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:Source1->IfcLabel_1:IfcLabel0
IfcLabel_2
IfcLabel
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:Name1->IfcLabel_2:IfcLabel0
IfcIdentifier_1
IfcIdentifier
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:ReferenceTokens1->IfcIdentifier_1:IfcIdentifier0
IfcLabel_3
IfcLabel
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:Edition1->IfcLabel_3:IfcLabel0
IfcText_1
IfcText
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:Description1->IfcText_1:IfcText0
IfcURIReference_0
IfcURIReference
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:Location1->IfcURIReference_0:IfcURIReference0
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcDate.htm'>IfcDate</a>
IfcDate
<a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcClassification.htm'>IfcClassification</a>:EditionDate1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcDate.htm'>IfcDate</a>:IfcDate0
Figure 4.1.2.2.A
General UsageTable 4.1.2.2.B