Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
FileRequest interface extends the
DOMRequest interface to provide some extra properties necessary for the
FileRequest also inherits properties from the
FileRequest.lockedFile Read only
LockedFile object from which the request was started.
A callback handler called repeatedly while the operation represented by the
FileRequest is in progress.