A few of us on the chrome team just discussed this. We see this as a deficiency in the FormData interface and intend to address it by providing a variant of FormData.append(...) that allows the caller to provide a 'filename' when appending a blob. We don't intend to implement BlobBuilder.getFile().
Anne, would you be willing to massage the XHR2 spec to allow for the additional param in the case of a blob? On Mon, Jul 18, 2011 at 3:00 PM, Jonas Sicking <[email protected]> wrote: > On Mon, Jul 18, 2011 at 2:52 PM, Charles Pritchard <[email protected]> > wrote: > > On 7/18/2011 2:42 PM, Jonas Sicking wrote: > >>> > >>> > If there is an API that replies on File to > >>> > work correctly we think we should fix it to work with Blob. For > >>> > example, FileReader is > >>> > really BlobReader and works fine with Blobs. To me, getFile() should > >>> > be unnecessary and > >>> > the best fix for FormData is to just modify append for this > situation. > >> > >> While File and Blob are indeed very similar, they are also not the > >> same thing. I think being able to create files is an easy addition for > >> implementations, while it means not restricting getting Files from the > >> users file system. So if you have code that expects to read a File > >> from IndexedDB, the page can either populate that from the users > >> filesystem, or by generating the data manually and using > >> BlobBuilder.getFile. > > > > I'm very interested in this use case; I've been told that there may be > > issues > > with IndexedDB transaction constraints and FileReader/writer. > > > > Afaik, filewriter doesn't apply to blobs in this case. I don't know the > > consequences of > > callbacks to reader functions in the event loop, and whether that would > end > > up "blocking" > > idb events. I'd imagine the blob is simply reset, and the stale reference > > remains until it can > > be cleaned up. > > Note that File objects are immutable just like Blobs are, so none of > this applies here. > > The issues that you're talking about come up once we start talking > about FileEntries, but that's an entirely different beast which are > unrelated to this thread. No-one has suggested being able to create a > FileEntry using BlobBuilder, nor that FileEntries are required to > submit named content using FormData. > > Hope that helps. > > / Jonas > >
