UA support for Content-Disposition header (filename parameter)

Here's a problem that plagued me a few years ago, and I'm pretty sure 
the situation hasn't improved since then, at least not in IE. Maybe 
HTML5 should say something about it.

Use case: have the UA offer a "save as" dialogue, including the filename.

Mechanism: Content-Disposition HTTP header, as defined in RFC2616 
(<http://greenbytes.de/tech/webdav/rfc2616.html#rfc.section.19.5.1>)

Example:

   Content-Disposition: attachment; filename=fname.ext

Problem: this works fine in all browsers, as long as the filename does 
not contain non-Latin1 characters.

RFC 2231 (<http://greenbytes.de/tech/webdav/rfc2231.html>) defines an 
escaping, and that is supported by Firefox. Example:

   Content-Disposition: attachment; filename*=utf8''D%C3%BCrst.ext

IE does not support RFC 2231 (as of IE7), but allows percent escaped 
UTF-8, such as in:

   Content-Disposition: attachment; filename=D%C3%BCrst.ext

However, that only works when IE is configured for UTF-8 URL encoding, 
which is (as far as I recall) not the default in countries using Asian 
languages.

Proposal: require UAs to support RFC 2231 (UTF-8 variant).

BR, Julian

Received on Friday, 14 March 2008 13:49:17 UTC