Protected	`function WantsGlobalId: Boolean; virtual;`
Protected	`class function IfcClassName: String; virtual;`
Public	`constructor Create(AOwner: TComponent); override;`
Public	`destructor Destroy; override;`

Properties

Published	`property GlobalId: String read FGlobalId write FGlobalId;`
Published	`property HasExternalReferences: TIfcExternalReferenceRelationshipList read FHasExternalReferences;`
Published	`property Name: TIfcIdentifier read FName write FName;`
Published	`property Description: TIfcText read FDescription write FDescription;`
Published	`property Properties: TIfcPropertyList read FProperties;`
Published	`property Material: TIfcMaterialDefinition read FMaterial write FMaterial;`

Description

Methods

Protected function WantsGlobalId: Boolean; virtual;

This item is declared in ancestor TIfcPersistent.

If True, instances of this class will have GlobalId auto-assigned at saving, and they will be saved as part of the "data" list in IFC JSON files.

Strictly following the spec, this should be only defined for TIfcRoot, because only IfcRoot has GlobalId. In reality, we need GlobalId at TIfcPersistent to load some files, and we sometimes need WantsGlobalId = True to save some files.

Source: scene/load/ifc/castleifc_ifc_types.inc (line 52).

Protected class function IfcClassName: String; virtual;

This item is declared in ancestor TIfcPersistent.

Name for the IFC standard, used in IFC files. By default, this is just ClassName with prefix 'T' removed.

Source: scene/load/ifc/castleifc_ifc_types.inc (line 56).

Public constructor Create(AOwner: TComponent); override;

This item is declared in ancestor TIfcExtendedProperties.

This item has no description.

Source: scene/load/ifc/castleifc_ifc_standard_types.inc (line 5311).

Public destructor Destroy; override;

This item is declared in ancestor TIfcExtendedProperties.

This item has no description.

Source: scene/load/ifc/castleifc_ifc_standard_types.inc (line 5312).

Properties

Published property GlobalId: String read FGlobalId write FGlobalId;

This item is declared in ancestor TIfcPersistent.

Globally unique identifier for the object instance.

Note: Not declared as TGUID, because TGUID cannot be published, but also we don't really need it: for our purposes, this identifier is just an arbitrary string.

Note: IFC 4.3 specification puts this only at IfcRoot, not at every IFC class. But testcase https://github.com/buildingsmart-community/Community-Sample-Test-Files/blob/main/IFC%204.0.2.1%20(IFC%204)/ISO%20Spec%20archive/wall-with-opening-and-window.json (from IFC 4.0) shows this can be present at any IFC class, in particular TIfcGeometricRepresentationContext.

In fact, TIfcGeometricRepresentationContext needs to have GlobalId to be successfully saved (avoid recursively trying to serialize it) in some cases. We indicate such classes with WantsGlobalId.

IFC JSON documentation says this, which seems to (unfortunately it is not unambiguous enough...) allow this at any IFC class: "Whereas the globalId attribute is only available to those elements that are descendent of the IfcRoot entity in the EXPRESS schema, we encourage a broader use of this globalId, to enable referencing between objects in a JSON file when useful.".

Source: scene/load/ifc/castleifc_ifc_types.inc (line 79).

Published property HasExternalReferences: TIfcExternalReferenceRelationshipList read FHasExternalReferences;

This item is declared in ancestor TIfcPropertyAbstraction.

Reference to an external reference, e.g. library, classification, or document information, that is associated to the property definition.

Source: scene/load/ifc/castleifc_ifc_standard_types.inc (line 5300).

Published property Name: TIfcIdentifier read FName write FName;

This item is declared in ancestor TIfcExtendedProperties.

The name given to the set of properties.

Source: scene/load/ifc/castleifc_ifc_standard_types.inc (line 5315).

Published property Description: TIfcText read FDescription write FDescription;

This item is declared in ancestor TIfcExtendedProperties.

Description for the set of properties.