Foundation User Defaults The power of UserDefaults in Swift Type-safe User Defaults File Wrapper FileWrapper Using FileWrappers as File Containers Working with File Wrappers in Swift UIDocument UIDocument Creating NSDocument using Folder Bundles and UTI Identifiers UIDocument From Scratch UIDocument & NSFileWrapper - large files taking a long time to save, despite incremental changes Formatting https://nshipster.com/formatter/ App Extension Support NSItemProvider Creating a NSItemProvider for custom model class (Drag & Drop API) NSItemProvider