640534 - dataTransfer.files does not exist while dragover and dragenter

Status: RESOLVED INVALID

(Core :: DOM: Copy & Paste and Drag & Drop, defect)

Description

[Leonard Weigand]

User-Agent:       Mozilla/5.0 (Windows NT 6.0; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0
Build Identifier: Mozilla/5.0 (Windows NT 6.0; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0

In the new DragnDrop API
the dataTransfer.files variable is set to null while hovering a drop target with some local files - you can access it with the drop event.
It should be available for dragenter and maybe also for dragover, so the developer of the site can forbid dropping files.

Thank you and sorry for not speaking perfectly English,
Leo

Reproducible: Always

Comment 1

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

You want to search dataTransfer.type for "Files"[1]; you can't see the files themselves until the user drops the files for security reasons.

[1] https://developer.mozilla.org/En/DragDrop/DataTransfer#types

Comment 2

[Leonard Weigand]

So all I have to do is to call dataTransfer.types[0] to check whether files are dragged over? Thanks, I thought it must have been a bug because Chrome and Safari behave in a different way..
Best Regards, Leo

Comment 3

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

I think you want dataTransfer.types.contains("Files"), since it's not guaranteed to be the first type.

Comment 4

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

Though, .contains won't work in chrome.  You'll want to loop through dataTransfer.types and test all of the types for "Files".

Comment 5

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

The relevant webkit bug is https://bugs.webkit.org/show_bug.cgi?id=30416