fromJson property

A Function to use when decoding the associated JSON value to the annotated field.

Must be a top-level or static Function or a constructor that accepts one positional argument mapping a JSON literal to a value compatible with the type of the annotated field.

When creating a class that supports both toJson and fromJson (the default), you should also set toJson if you set fromJson. Values returned by toJson should "round-trip" through fromJson.