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Re: LINK & UNLINK Methods

From: Roy T. Fielding <fielding@kiwi.ICS.UCI.EDU>
Date: Wed, 26 Mar 1997 23:01:59 -0800
To: Yaron Goland <yarong@microsoft.com>
cc: w3c-dist-auth@w3.org
Message-ID: <9703262302.aa27348@paris.ics.uci.edu>
>Actually Jim, URIs are tokens and thus do not have spaces. As the HTTP
>spec requires spaces between all tokens (please see section 2.1 of RFC
>2068), your quotes are unnecessary.

Huh? URIs are not tokens and whitespace is not a reliable separator in
header fields.  I must have said that a couple thousand times on http-wg,
and one was just last week.  If you want to separate URIs from parameters
in a header field, you must surround the URI with <angle brackets> or
"double-quotes", since they are the only characters that will never
appear within a URI even if it is broken across more than one line.

>Also if the Link header is going to be dumped from the HTTP spec then
>there is no backwards compatibility to be worried about and we can
>format the header properly, which should be:
>Link = "Link" ":" Source Destination Type *(";" link-param)

If you are going to redefine the syntax, then 

   Link       = "Link" ":" 1#( link-type *(";" link-param) )
   link-type  = token
   link-param = ( "from" "=" <"> URI <"> )
              | ( "to"   "=" <"> URI <"> )
              | ( token [ "=" ( token | quoted-string ) ] )

otherwise, the HTTP/1.1 spec defines it as

  if rel=type

       <first URI> is destination
       anchor="URI" is source (current document if elided)

  else if rev=type

       <first URI> is source
       anchor="URI" is destination (current document if elided)

I don't like that model, but it was inherited from HTML.

>Also, if the link header is going away then we can forget all the
>non-dav parameters. After all, no need to define the relationship with
>non-existent parameters. If it isn't in the HTTP 1.1 spec, it isn't our
>problem.

Extensibility is a WEBDAV problem.

....Roy
Received on Thursday, 27 March 1997 02:14:27 GMT

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