Extensions generate a diagram automatically from a data source.
SmartDraw has some built-in extensions that let you generate diagrams like a class diagram or database diagram automatically. You can also make your own.
To do so, navigate to the Extension section on the main template dialog you see when SmartDraw starts up and click on Create an Extension under Custom Extensions.
You can choose between two ways of creating an extension.
Read the following tutorials on how to create an extension with the two methods available: