Platform: accessing DataTransferItems during external drag (before drop)

[psychedelicious]

The docs say:

Due to the web platform drag and drop security model, you can know what "types" are being dragging during a drag (eg "text/plain"), but you can only see what data is being dragged (exposed through .items) during a successful "drop" event (onDrop()).

https://atlassian.design/components/pragmatic-drag-and-drop/core-package/adapters/external/about#monitor-for-external

However, it looks like I can access the items using the native dnd API as seen in this demo: https://stackblitz.com/edit/vitejs-vite-cgmywj?file=src%2FApp.tsx

I was confused about this until I realized I only get the items on Chrome and FF - not Safari.

• Who is implementing the spec correctly - Chrome & FF or Safari?
• If Chrome & FF are adhering to the spec, can we expect pdnd to expose items during drag events once Safari catches up?
• Are there any suggested workarounds to provide user feedback as soon as a drag starts? I'd like to be able to, for example, enable some drop targets only when the drag has image files.

Thanks!

---

Some context, in case this helps anyone else who is migrating to pdnd and confused by this.

I was porting from react-dropzone. You provide file constraints to the useDropzone hook, and it uses those for validation when the drag starts. As I migrated the constraints to pdnd, I was puzzled when I didn't get any items to validate in my canDrop callback. I double-checked the native events and saw the items.

Like native events, react-dropzone provides items during drag on Chrome & FF but not Safari. On Safari, it handles any drag as invalid. I had apparently never tested our react-dropzone dnd implementation with Safari until now.