Learning > presentation > hierarchies > Instance Nodes Of Specific Classes

InstanceNodesOfSpecificClasses

Returns nodes for instances of specific ECClasses.

Attributes

Name	Required?	Type	Default	Meaning	Performance Notes
Filtering
`classes`	Yes	`MultiSchemaClassesSpecification \| MultiSchemaClassesSpecification[]`	`[]`	Classes whose instances should be used.
`handleInstancesPolymorphically`	No	`boolean`	`false`	Should instances be queried using a polymorphic query - from `classes` and all their subclasses. This doesn't mean the resulting content will have all properties of the subclasses though - they're only taken from base classes specified in `classes` attribute.
`instanceFilter`	No	ECExpression	`""`	Condition for filtering instances
`hideNodesInHierarchy`	No	`boolean`	`false`	Hide nodes provided by this specification and directly show their children.	Expensive
`hideIfNoChildren`	No	`boolean`	`false`	Hide nodes if they don't have children.	Expensive
Ordering
`priority`	No	`number`	`1000`	Changes the order of specifications used to create nodes for specific branch.
`doNotSort`	No	`boolean`	`false`	Suppress default sorting of nodes returned by this specification.	Improves
Grouping
`groupByClass`	No	`boolean`	`true`	Group instances by ECClass
`groupByLabel`	No	`boolean`	`true`	Group instances by label	Expensive
Misc.
`hasChildren`	No	`"Always" \| "Never" \| "Unknown"`	`"Unknown"`	Tells the rules engine that nodes produced using this specification always or never have children.	Improves
`relatedInstances`	No	`RelatedInstanceSpecification[]`	`[]`	Specifications of related instances that can be used in nodes' creation.
`nestedRules`	No	`ChildNodeRule[]`	`[]`	Specifications of nested child node rules.

Example

{
  "specType": "InstanceNodesOfSpecificClasses",
  "groupByClass": false,
  "groupByLabel": false,
  "classes": {
    "schemaName": "BisCore",
    "classNames": ["GeometricElement2d", "GeometricElement3d"]
  },
  "arePolymorphic": true
}

Last Updated: 13 June, 2024