Bundles, a draft specification

[Thomas Leonard]

On Mon, 03 Sep 2007 18:42:52 +0000, Mildred wrote:

> Le Mon 03/09/2007 à 17:45 Thomas Leonard à écrit:
>> On Sun, 02 Sep 2007 12:20:12 +0200, Mildred wrote:
>> 
>> In what way are they handled differently?`
> 
> Normal directories, when you open them, you can view its contents in the
> file manager. Bundles are like files in the sense that they have a mime
> type different from inode/directory and when you open them, it's
> generally with an appropriate application that will do specific things.

OK, so you want to give a MIME type (a subclass of inode/directory) to a 
directory. You can do that already like this:

$ mkdir my-web-page
$ setfattr -n user.mime_type -v bundle/html_files my-web-page 
$ getfattr -n user.mime_type my-web-page                     
# file: my-web-page
user.mime_type="bundle/html_files"

However, I'm not sure any file manager currently supports that. It would 
be interesting to try and get support added to various file managers.

>> Why are the MIME types not stored in the same way as for normal
>> directories? i.e. as extended attributes (if specified at all), or
>> guessed from the name or contents of the file otherwise.
> 
> Because extended attributes are not relyable (it depends upon the
> filesystem).

No system is reliable if it's not supported. For example, in your 
proposed system if a user moves or renames a file using a non-bundle-
aware program then the type information will get out-of-sync. Types will 
also be lost when copying out of a bundle.

On the other hand, existing tools should preserve attributes:

$ touch my-web-page/image
$ setfattr -n user.mime_type -v image/png my-web-page/image        
$ mv my-web-page/image my-web-page/picture
$ getfattr -n user.mime_type my-web-page/picture 
# file: my-web-page/picture
user.mime_type="image/png"

I'd prefer to see wider support for the existing mechanisms than trying 
to create a new system. That might mean persuading distributions to 
enable extended attributes by default.

Another point from the spec:

  When a bundle must be copied or moved in a media that only accept
  files and not folders, the bundle MUST be transformed into a ZIP bundle.

Why not do this for all directories, not just bundles?


-- 
Dr Thomas Leonard		http://rox.sourceforge.net
GPG: 9242 9807 C985 3C07 44A6  8B9A AE07 8280 59A5 3CC1