API Reference > presentation-common > PresentationRules > RelatedInstanceSpecification

RelatedInstanceSpecification Type alias

This sub-specification allows joining the primary node instance with any number of related instances and creating hierarchies based on a mix of those related instances.

The related instance property values can be accessed from multiple different places:

  • Instance filter
  • Customization rule value
  • Grouping rule

Example:

{
  "id": "related_instance_example",
  "rules": [{
    "ruleType": "LabelOverride",
    "condition": "ThisNode.IsInstanceNode ANDALSO this.IsOfClass(\"Model\", \"BisCore\")",
    "label": "modeledElement.UserLabel"
  }, {
    "ruleType": "Grouping",
    "condition": "ParentNode.IsNull",
    "class": {
      "schemaName": "BisCore",
      "className": "Element"
    },
    "groups": [{
      "specType": "Property",
      "propertyName": "CodeValue",
      "createGroupForSingleItem": true
    }]
  }, {
    "ruleType": "RootNodes",
    "specifications": [{
      "specType": "InstanceNodesOfSpecificClasses",
      "classes": { "schemaName": "BisCore", "classNames": ["GeometricModel"] },
      "arePolymorphic": true,
      "instanceFilter": "modeledElement.CodeNamespace = 1",
      "relatedInstances": [{
        "relationshipPath": [{
          "relationship": { "schemaName": "BisCore", "className": "ModelModelsElement" },
          "direction": "Forward",
        }],
        "class": { "schemaName": "BisCore", "className": "Element" },
        "alias": "modeledElement"
      }]
    }]
  }]
}

Here BisCore:GeometricModel instances are joined with BisCore:Element instances to create the hierarchy. This allows:

  • Related BisCore:Element properties to be accessed in InstanceFilter using modeledElement alias.
  • The LabelOverride rule to use modeledElement alias to access properties of the joined related instance.
  • The GroupingRule to be applied because it's grouping BisCore:Element which is now part of the generated nodes.

see More details

RelatedInstanceSpecification = DEPRECATED_RelatedInstanceSpecification | RelatedInstanceSpecificationNew

Defined in

Last Updated: 29 November, 2022