Williams, Stuart (HP Labs, Bristol) wrote:
Well there are ways around that, add a package description
or meta-data file either at the root of the package or at
each directory level and have it carry media-type information
- or use 'magic numbers' or (if you really must - in the
absense of other authoritative information), sniff/guess
though I think that should be the least preferred option.
Right. The new proposal is that we use file extension mappings to MIME
types, and if that fails, result to sniffing. We are reluctant to
introduce a meta-data format at this point.
(Just allow RDFa+XHTML and leave it to the marketplace...)
For version 2 of widgets,
it might be useful to either introduce the meta-data format or have
an Apache-like file extensions to MIME type mapping. For example:
image/gif .gif
Note however, that widget engine in the wild have no problem working
without MIME info. From what I have seen, they all do just fine either
sniffing or using file extensions to derive the content types.
Anyway - that zip files don't intrinically maintain such
info is not a show stopper - though I would have thought that
carrying media-type information is a natural requirement for
a packaging format for the web.
I'm not sure it is. When a MIME type is registered with IANA, the file
extension is also registered.
What is registered (RFC 4288 section 4.11) is a list of file name extensions
commonly used with the media-type.
It does *not* reserve the extension for exclusive use with that media-type.
It does *not* prevent other arbitrary file name extension or indeed
no-extension being used.
So... yes not a bad hint, but nothing is certain.
So one has a standardized way to derive
the media type for a file by the file extension.
Not with certainty...
So this seems like a very small piece of metadata ('this filetree
follows the IANA filename to media type mappings') has a lot of value.
If the versions of the IANA mapping are easily identified, the metadata
becomes a URI rather than a single bit. Either way, you can gain a lot
from not a lot, I think.
cheers,
Dan
--
http://danbri.org/
