Nutrient 3.3 migration guide

In Nutrient Flutter SDK 3.3, we moved package files from lib/src to lib. To update your code, change your pspdfkit_flutter package imports as follows:

-import 'package:pspdfkit_flutter/src/widgets/pspdfkit_widget.dart';
+import 'package:pspdfkit_flutter/pspdfkit_widget.dart';

We also updated main.dart to pspdfkit.dart. This means that the PSPDFKit static class import will now be as follows:

-import 'package:pspdfkit_flutter/src/main.dart';
+import 'package:pspdfkit_flutter/pspdfkit.dart';