Note that the Diagram widget is in the community technology preview (CTP) development stage.
The Diagram widget accepts functions as expression property values. The widget allows you to implement custom logic when you bind a diagram to a data source. In this demo, the nodes and edges collections are bound to a data source. Custom functions are used to get different shape types and font styles for items based on additional data source information.
The autoLayout option specifies an auto-layout algorithm type and orientation that the widget uses to build diagrams.