Why no files were attached: PERMISSION_DENIED when the token was unknown, expired, already spent, superseded by a later prepareDrag or minted for another window; INVALID_PARAMS when dataTransfer.effectAllowed was not exactly copy, which dnd.applyDragToken sets correctly; OPERATION_FAILED when the file list could not be attached to the drag.
Human-readable error description; physical paths are omitted.
Always failed: the host reports only refusals.
Payload of the
dnd:dragEndedevent. The host attached no files to a drag out of the window, decided at the moment the drag started. The drag itself goes on as an ordinary page drag without files, so a drop inside the page still works; the token text is blanked first, and in the rare case that it cannot be the drag is cancelled instead. It is not a completion notice: when the host accepts the token and hands the files over, nothing follows, and the page's owndragendreports the outcome throughdataTransfer.dropEffect(copywhen a target took the files,nonewhen the drag was cancelled or refused). Only a drag that carried a drag token can cause it; a page dragging its own text, image or link never does.