API Reference > presentation-common > PresentationRules > ContentInstancesOfSpecificClassesSpecification ContentInstancesOfSpecificClassesSpecification Interface Creates content for ECInstance(s) of specified classes. Note: this specification doesn't rely on selection. It always returns instances no matter what the selection is, so pre-filtering should be done in ContentRule condition and ContentInstancesOfSpecificClassesSpecification.instanceFilter. see More details Extends ContentSpecificationBase Properties Name Type Description arePolymorphic undefined | boolean Whether to get content from instances of derived classes. Deprecated classes MultiSchemaClassesSpecification | MultiSchemaClassesSpecification[] List of ECClass specifications whose ECInstances should be selected. handleInstancesPolymorphically undefined | boolean Whether to get content from instances of derived classes. handlePropertiesPolymorphically undefined | boolean Whether to get content from properties of derived classes. instanceFilter undefined | string Condition for filtering instances of defined classes. specType ContentInstancesOfSpecificClasses Used for serializing to JSON. Inherited properties Name Type Inherited from Description calculatedProperties undefined | CalculatedPropertiesSpecification[] ContentSpecificationBase Specifications for including calculated properties priority undefined | number ContentSpecificationBase Defines the order in which specifications are evaluated and executed. propertiesDisplay undefined | DEPRECATED_PropertiesDisplaySpecification[] ContentSpecificationBase Specifications for customizing property display by hiding / showing them propertyCategories undefined | PropertyCategorySpecification[] ContentSpecificationBase Specifications for custom categories. propertyEditors undefined | DEPRECATED_PropertyEditorsSpecification[] ContentSpecificationBase Specifications for assigning property editors propertyOverrides undefined | PropertySpecification[] ContentSpecificationBase Specifications for various property overrides. relatedInstances undefined | RelatedInstanceSpecification[] ContentSpecificationBase Specifications for joining related instances relatedProperties undefined | RelatedPropertiesSpecification[] ContentSpecificationBase Specifications for including properties of related instances showImages undefined | boolean ContentSpecificationBase Should each content record be assigned an image id Defined in presentation/common/src/presentation-common/rules/content/ContentInstancesOfSpecificClassesSpecification.ts Line 21 Last Updated: 29 November, 2022