Never ending uploads with DropBox document picker export mode

I don't think there should be anything special about using UIDocumentPickerModeExportToService with Dropbox in particular. 

Can you share some sample code and steps to reproduce the issue so we can look into it? Thanks in advance! 

Thanks Gregory for your help!

The backup is a document bundle with a custom extension '.pwbackup', so may be there is something wrong with exporting a directory like that to Dropbox, and it would be better to create a zip archive.

To do the export,  inside my app document directory I prepare a backup bundle, that contains a SQLite database, some attachments and a property list, then I present a UIDocumentMenuViewController:

let menu = UIDocumentMenuViewController(URL: backupURL, inMode: .ExportToService)

presentViewController(menu, animated: true, completion: nil)

When the user chooses the picker in the menu, I present it with:

func documentMenu(documentMenu: UIDocumentMenuViewController, didPickDocumentPicker documentPicker: UIDocumentPickerViewController) {

    documentPicker.delegate = self

    presentViewController(documentPicker, animated: true) { }

}

When the document picker is done, I get rid of the backup I prepared locally. With Dropbox, this part is never called, since the transfer doesn't succeed:

func documentPicker(controller: UIDocumentPickerViewController, didPickDocumentAtURL url: NSURL) {

    try NSFileManager().removeItemAtURL(backupURL)

} 

In my app Info.plist, I have the following exported UTIs:

<key>UTExportedTypeDeclarations</key>

<array>

<dict>

<key>UTTypeConformsTo</key>

<array>

<string>public.composite-content</string>

<string>public.database</string>

<string>com.apple.package</string>

</array>

<key>UTTypeDescription</key>

<string>Placeboard Backup</string>

<key>UTTypeIdentifier</key>

<string>com.placeboardapp.backup</string>

<key>UTTypeTagSpecification</key>

<dict>

<key>public.filename-extension</key>

<array>

<string>pwbackup</string>

</array>

</dict>

</dict>

</array>

Let me know if you need some additional info or code.

Thanks for the additional information Quentin! I believe that is in fact the issue, in that the Dropbox document picker doesn't currently support folders/packages, so sending a zip file would be better. I'm sending this along as a feature request though.

ok, I'll tweak the code to upload a zip file. 

btw is there a page on Dropbox website that documents these APIs limitations?

Until uploading folders with the document picker is supported by Dropbox, it could also be nice to show a dialog explaining it's not possible.

Thanks for the quick reply!

Thanks for the feedback! We don't currently have documentation for this, but I'll be sure to pass this along as a request for some.