Getting the contents of a drag from Preview

In Preview it’s possible to select one or more thumbnails and drag them to the Finder to create a new PDF containing just those pagesl. I’d like my app to accept these drags and file the new PDF according to user-defined rules. According to the documentation I’ve read, the drag should contain a file promise, which according to the LR I should be able to access with obj.RawData(“phfs”). But there is no such item when I query the drag object. I’ve used Clipboard Viewer to see what Preview puts there if you Copy the thumbnails, and there is indeed the promised file. The drag object does contain the data type “com.adobe.pdf”, but that is the PDF of only the first page, not all pages. My question is, does anyone know what the data type in the drag contains either the entire PDF or the path to the new file? Failing that, does anyone know of a utility that will let you see the contents of a drag Pasteboard the way Clipboard Viewer lets you see the contents of the clipboard Pasteboard?

Cool. Thanks for the link, and thanks to @Sam Rowlands.