Pega Platform provides a pair of data transforms (pyDefault and pySetFieldDefaults) that are used to automatically set default property values and page properties when you create a case.
The first time you create a view for your case type in the Case Designer, Pega Platform creates these data transforms. You can also create these data transforms manually. When a new case is created, the pyDefault data transform is invoked by the process. pyDefault then invokes the pySetFieldDefaults data transform.
Similar to pyDefault, you can use the pySetFieldDefaults data transform to set default values for properties. In addition, you use pySetFieldDefaults to automatically initialize page (field group) and page list (field group list) properties. When pyDefault invokes pySetFieldDefaults, properties are immediately available to the case when it is created.
Because the pyDefault data transform is always invoked when a case is created, pyDefault includes the Apply Data Transform action. This ensures that pySetFieldDefaults is also invoked when a case is created. This action does not use Relation or Source settings.
"pySetFieldDefaults" data transform can be Utilized in form configuration for fields that are generated for a case type.
"pyDefault" data transform in your case type class will Call superclass data transform. You can refer the "pyDefault" data transform of Work- class to see the values of OOTB properties it initializes while creating a case instance.