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Default BIS Presentation Rules

iTwin.js delivers a supplemental presentation ruleset that gets automatically merged into all presentation rulesets that support BisCore ECSchema. The ruleset provides default behavior for various BIS types: Elements, Models, etc.

Label Overrides

Label override rules are used when we calculate ECInstance display labels for trees, property grid and other components. Below is the algorithm for calculating the labels.

  • For BisCore:GeometricElement and it's subclasses:
    1. Use CodeValue. If empty, go to #2.
    2. Use UserLabel [base36(briefcase id)-base36(local id)]. If UserLabel empty, go to #3.
    3. Use ECClassLabel [base36(briefcase id)-base36(local id)].
  • For all other BisCore:Element subclasses:
    1. Use UserLabel. If empty, go to #2.
    2. Use CodeValue. If empty, go to #3.
    3. Use ECClassLabel [base36(briefcase id)-base36(local id)].
  • For all BisCore:Model subclasses:
    1. Use modeled Element's label (calculated using the above)

briefcase id and local id are calculated from Element's id:

  • briefcase id = element id >> 40
  • local id = element id & (1 << 40 - 1)

Content Modifiers

Content modifier rules are applied when creating content for property grid, table and similar components. Each modifier is applied on specific types of ECInstances.

BisCore:Element

  • Append properties
    • of all related BisCore:ElementUniqueAspects through BisCore:ElementOwnsUniqueAspect forward relationship
    • of all related BisCore:ElementMultiAspects through BisCore:ElementOwnsMultiAspects forward relationship
    • of all related BisCore:LinkElements through BisCore:ElementHasLinks forward relationship
    • of all related BisCore:GroupInformationElements through BisCore:ElementGroupsMembers backward relationship
      • and their related BisCore:LinkElements through BisCore:ElementHasLinks forward relationship
    • 'Identifier' as 'Source Element ID' of related BisCore:ExternalSourceAspect through BisCore:ElementOwnsMultiAspects forward relationship into the 'Source File Information' category
    • 'Url' as 'Source File Path' and 'UserLabel' as 'Source File Name' of related BisCore:RepositoryLink through BisCore:ModelContainsElements -> BisCore:Model -> BisCore:ModelModelsElement -> BisCore:PhysicalPartition | BisCore:Drawing -> BisCore:ElementHasLinks path.

BisCore:PhysicalElement

  • Append properties
    • of all related BisCore:PhysicalTypes through BisCore:PhysicalElementIsOfType forward relationship

BisCore:SpatialLocationElement

  • Append properties
    • of all related BisCore:SpatialLocationTypes through BisCore:SpatialLocationIsOfType forward relationship

BisCore:DrawingGraphic

  • Append properties
    • of all related BisCore:Elements through BisCore:DrawingGraphicRepresentsElement forward relationship

BisCore:GraphicalElement3d

  • Append properties
    • of all related BisCore:Elements through BisCore:GraphicalElement3dRepresentsElement forward relationship

BisCore:PhysicalType

  • Hide all properties (excluding subclass properties)

BisCore:SpatialLocationType

  • Hide all properties (excluding subclass properties)

BisCore:LinkElement

  • Hide CodeValue and UserLabel properties

BisCore:UrlLink

  • Hide Description property

BisCore:EmbeddedFileLink

  • Hide Description property

Last Updated: 15 June, 2021