Re: Last Call: draft-nottingham-http-link-header (Web Linking) to Proposed Standard

On Mon, Sep 21, 2009 at 10:17 AM, Mark Nottingham <mnot@mnot.net> wrote:

>
> Nevertheless -- how do other people feel about restricting to one rel
>> attribute in the Link header? Looking back at 2068, the BNF implicitly
>> allows multiple rel values, but it isn't explicitly addressed in the prose,
>> so Ian does have a point -- you could see it either way.
>>
>
> I've just added:
>
> The "rel" parameter MUST NOT appear more than once in a given link-value;
> occurrences after the first MUST be ignored by parsers.
>
> and adjusted the examples to suit. Does that address your concern?


Looks good.


>  As far as how it works in UI -- present the most appropriate title based
>>>> upon the users preferences.
>>>>
>>>
>>> Could you give a concrete example of a Link: header that uses multiple
>>> titles in this way and describe what you think the ideal UI for that
>>> example would be?
>>>
>>
>>  Link: </TheBook/chapter6>; rel="last"; title*=UTF-8'de'letztes%20Kapitel;
>> title*=UTF-8'en'final%20chapter
>>
>> One example of a UI -- if it chooses to use the title instead of the URL
>> for displaying the link (e.g., in a toolbar dedicated to showing links)
>> would use the first title* if the users configured language was German, and
>> the second if it were English.
>>
>
> I've just changed the 'title'-related text to:
>
> The "title" parameter, when present, is used to label the destination of a
> link such that it can be used as a
> human-readable identifier (e.g. a menu entry). The "title" parameter MUST
> NOT appear more than once in a given link-value;
> occurrences after the first MUST be ignored by parsers.
>
> The "title*" parameter MAY be used encode this label in a different
> character set, and/or contain language information as per
> <xref target="RFC2231"/>. When using the enc2231-string syntax, producers
> MUST NOT use a charset value other than 'ISO-8859-1'
> or 'UTF-8'. The "title*" parameter MAY appear more than once in a given
> link-value, but each occurrence MUST indicate a
> different language; occurrences after the first for a given language MUST
> be ignored by parsers.
>
> When presenting links to users, agents SHOULD use the most appropriate
> "title*" value, according to user preferences. If
> an appropriate "title*" value cannot be found, the "title" parameter's
> value, if available, can be used.
>
> Does this work?


While this may or may not always be the case for Atom, for HTTP and HTML the
document is subject to the usual HTTP conneg, which includes languages. If
you're retrieving the document itself in French then presumably you want the
title (including non-ASCII characters) in French too. I've said this before
but I still don't grok [from the document] why both are required.

Sam