parentId (default: "{ type: 'number', nullable: true }")

The name of the Model's parentId field. The Kendo UI TreeList distinguishes the root items based on the parentId field. If the schema.model.fields.[parentIdField] is nullable, root items with be items whose parentId field values are null. If the schema.model.fields.[parentIdField] is not nullable, root items will be items which have a default value for their data type.