Directory Upload

Hello WebApps WG and Incubator CG members,

As you may know, we (Microsoft) have been collaborating with Mozilla on evolving the new directory 
upload proposal [1]. It has recently been added to the Incubator Community Group and we are looking 
forward to have everyone get involved with providing feedback on this initial proposal. If you haven't 
already made a first-pass read of the spec, I invite you to take some time to do that as it is a 
relatively short document that we are trying to get some more eyes on.

As we wait for the spec to stabilize, and to solve the existing interop gap with Chrome with regards 
to directory uploads, we are implementing the webkitRelativePath property for the File interface and 
webkitdirectory attribute for the input tag [2]. This allows sites to show a directory picker and to 
identify the relative file structure of the directory a user selects.

Supporting webkit-prefixed properties is not an endorsement of the old way of doing it - it is an 
interop realization. For this reason, we will consider the webkit-prefixed API as deprecated in 
Microsoft Edge (as we do with other webkit-prefixed APIs we support for compatibility). The old 
API is synchronous and doesn't provide a natural way of traversing directories. That is why we 
are working closely with Mozilla and encouraging everyone in the community to look into the 
directory upload proposal and to provide feedback.

Thank you,
Ali

[1] https://wicg.github.io/directory-upload/proposal.html
[2] https://dev.modern.ie/platform/status/webkitdirectoryandwebkitrelativepath
[3] https://dev.modern.ie/platform/status/directoryupload/