HTML5 & Web Links (RFC 5988)
Now that RFC 5988 is a proposed standard [1] and HTML5 references the "Link:" header [2], has anyone plans to introduce such support into WebKit ? It seems like a straight forward behavior to adopt. At minimum, the CSS stylesheets specified in the Link: header would be inserted, in order, between the user agent stylesheets and the document's stylesheets. Are there any implementation issues that one could imagine with this RFC? There are some obvious interoperability questions until enough browsers sufficiently support this feature. [1] http://tools.ietf.org/html/rfc5988 [2] http://dev.w3.org/html5/spec/Overview.html#the-link-element -- --Alex Milowski "The excellence of grammar as a guide is proportional to the paucity of the inflexions, i.e. to the degree of analysis effected by the language considered." Bertrand Russell in a footnote of Principles of Mathematics
Alex, I'm hacking at this right now, and hope to have a CL uploaded soon. - Gavin On 9 November 2010 06:51, Alex Milowski <alex@milowski.org> wrote:
Now that RFC 5988 is a proposed standard [1] and HTML5 references the "Link:" header [2], has anyone plans to introduce such support into WebKit ? It seems like a straight forward behavior to adopt. At minimum, the CSS stylesheets specified in the Link: header would be inserted, in order, between the user agent stylesheets and the document's stylesheets.
Are there any implementation issues that one could imagine with this RFC?
There are some obvious interoperability questions until enough browsers sufficiently support this feature.
[1] http://tools.ietf.org/html/rfc5988 [2] http://dev.w3.org/html5/spec/Overview.html#the-link-element
-- --Alex Milowski "The excellence of grammar as a guide is proportional to the paucity of the inflexions, i.e. to the degree of analysis effected by the language considered."
Bertrand Russell in a footnote of Principles of Mathematics _______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Are there any specific link types we should support in the Link: header besides stylesheets? I know other browsers support Link to reference a stylesheet, so it's probably good for interop if we do it too. Regards, Maciej On Nov 9, 2010, at 3:51 AM, Alex Milowski wrote:
Now that RFC 5988 is a proposed standard [1] and HTML5 references the "Link:" header [2], has anyone plans to introduce such support into WebKit ? It seems like a straight forward behavior to adopt. At minimum, the CSS stylesheets specified in the Link: header would be inserted, in order, between the user agent stylesheets and the document's stylesheets.
Are there any implementation issues that one could imagine with this RFC?
There are some obvious interoperability questions until enough browsers sufficiently support this feature.
[1] http://tools.ietf.org/html/rfc5988 [2] http://dev.w3.org/html5/spec/Overview.html#the-link-element
-- --Alex Milowski "The excellence of grammar as a guide is proportional to the paucity of the inflexions, i.e. to the degree of analysis effected by the language considered."
Bertrand Russell in a footnote of Principles of Mathematics _______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
09.11.2010, в 03:51, Alex Milowski написал(а):
Now that RFC 5988 is a proposed standard [1] and HTML5 references the "Link:" header [2]
Note the way in which HTML5 references it: "Some versions of HTTP defined a Link: header". That's about HTTP 1.0 only. Specifying stylesheets in HTTP headers seems like a most obvious misfeature to me, and other potential uses of the Link header field are so unimportant that RFC 5988 doesn't even bother to mention them in its introduction. - WBR, Alexey Proskuryakov
On Nov 9, 2010, at 9:00 AM, Alexey Proskuryakov wrote:
09.11.2010, в 03:51, Alex Milowski написал(а):
Now that RFC 5988 is a proposed standard [1] and HTML5 references the "Link:" header [2]
Note the way in which HTML5 references it: "Some versions of HTTP defined a Link: header". That's about HTTP 1.0 only.
Specifying stylesheets in HTTP headers seems like a most obvious misfeature to me, and other potential uses of the Link header field are so unimportant that RFC 5988 doesn't even bother to mention them in its introduction.
It might be worth testing which other browsers support it. I know at least Firefox supports associating a stylesheet with Link. It does seem like a fairly ill-conceived feature, but not so much that it is worth being the sole holdout, if other browser engines all do it. And there are some plausible use cases - same document served with multiple stylesheets, without having to modify the document on the fly, just the headers. Regards, Maciej
Firefox supports it for rel=prefetch, and it was my thought to include that support in my patch. That use is worthwhile: it allows server specification of prefetch resources, as opposed to author (as in HTML).l - Gavin On 9 November 2010 12:20, Maciej Stachowiak <mjs@apple.com> wrote:
On Nov 9, 2010, at 9:00 AM, Alexey Proskuryakov wrote:
09.11.2010, в 03:51, Alex Milowski написал(а):
Now that RFC 5988 is a proposed standard [1] and HTML5 references the "Link:" header [2]
Note the way in which HTML5 references it: "Some versions of HTTP defined
a Link: header". That's about HTTP 1.0 only.
Specifying stylesheets in HTTP headers seems like a most obvious
misfeature to me, and other potential uses of the Link header field are so unimportant that RFC 5988 doesn't even bother to mention them in its introduction.
It might be worth testing which other browsers support it. I know at least Firefox supports associating a stylesheet with Link. It does seem like a fairly ill-conceived feature, but not so much that it is worth being the sole holdout, if other browser engines all do it. And there are some plausible use cases - same document served with multiple stylesheets, without having to modify the document on the fly, just the headers.
Regards, Maciej
_______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Even for prefetching this seem rather worthless as it won't allow prefetching start significantly earlier over the resources specified in the document source. There is also (based on the experience in similar things) a high chance that whatever is listed in the Link header won't match what the document actually uses and so will end up slowing down the page load. antti 2010/11/9 Gavin Peters (蓋文彼德斯) <gavinp@chromium.org>:
Firefox supports it for rel=prefetch, and it was my thought to include that support in my patch. That use is worthwhile: it allows server specification of prefetch resources, as opposed to author (as in HTML).l - Gavin
On 9 November 2010 12:20, Maciej Stachowiak <mjs@apple.com> wrote:
On Nov 9, 2010, at 9:00 AM, Alexey Proskuryakov wrote:
09.11.2010, в 03:51, Alex Milowski написал(а):
Now that RFC 5988 is a proposed standard [1] and HTML5 references the "Link:" header [2]
Note the way in which HTML5 references it: "Some versions of HTTP defined a Link: header". That's about HTTP 1.0 only.
Specifying stylesheets in HTTP headers seems like a most obvious misfeature to me, and other potential uses of the Link header field are so unimportant that RFC 5988 doesn't even bother to mention them in its introduction.
It might be worth testing which other browsers support it. I know at least Firefox supports associating a stylesheet with Link. It does seem like a fairly ill-conceived feature, but not so much that it is worth being the sole holdout, if other browser engines all do it. And there are some plausible use cases - same document served with multiple stylesheets, without having to modify the document on the fly, just the headers.
Regards, Maciej
_______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
_______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
09.11.2010, в 9:20, Maciej Stachowiak написал(а):
It might be worth testing which other browsers support it. I know at least Firefox supports associating a stylesheet with Link. It does seem like a fairly ill-conceived feature, but not so much that it is worth being the sole holdout, if other browser engines all do it.
Agreed. I don't know whether IE supports it, but given that this hasn't been a source of compatibility bugs, I suspect that it doesn't.
And there are some plausible use cases - same document served with multiple stylesheets, without having to modify the document on the fly, just the headers.
Yes, and that seems to be a (potential?) source of trouble for everyone, not just browser vendors. Surely one doesn't want to fight with a misconfigured hosting that forces a CSS stylesheet on their pages, or to discover that their own server was doing that, after spending an eternity analyzing their HTML source for mistakes. Moving or copying essential information about a document into HTTP headers is frustrating for charset declarations, why do that for anything else? With charsets, there is at least the explanation that many text formats don't have a place to declare it internally. - WBR, Alexey Proskuryakov
On Tue, Nov 9, 2010 at 6:01 PM, Alexey Proskuryakov <ap@webkit.org> wrote:
Moving or copying essential information about a document into HTTP headers is frustrating for charset declarations, why do that for anything else? With charsets, there is at least the explanation that many text formats don't have a place to declare it internally.
The charset parameter on the content-type header is more reliable than what is in the document. It also gives you a way to know how to decode the bytes into a character stream before you look into those bytes. The absence of a charset parameter requires the user agent to attempt strange things as the default character encoding for HTTP 1.1 is ISO-8859-1. In this way, it is very unlike the reservations some might have for the Link header. -- --Alex Milowski "The excellence of grammar as a guide is proportional to the paucity of the inflexions, i.e. to the degree of analysis effected by the language considered." Bertrand Russell in a footnote of Principles of Mathematics
10.11.2010, в 01:59, Alex Milowski написал(а):
Moving or copying essential information about a document into HTTP headers is frustrating for charset declarations, why do that for anything else? With charsets, there is at least the explanation that many text formats don't have a place to declare it internally.
The charset parameter on the content-type header is more reliable than what is in the document.
If you meant that it is authoritative, then yes, that's how it works. On the other hand, it's certainly not reliable. If you move your content to a different server, or just download it to a local file, the information is lost.
It also gives you a way to know how to decode the bytes into a character stream before you look into those bytes.
Yes, knowing charset in advance certainly simplifies things. But since it cannot always be present, clients need to have code that checks for charset declaration in content anyway.
In this way, it is very unlike the reservations some might have for the Link header.
I think that issues are the same - but as mentioned before, charset in HTTP headers is necessary for some types of content, and that's a good excuse for its existence. Link doesn't appear to ever be necessary. - WBR, Alexey Proskuryakov
participants (5)
-
Alex Milowski
-
Alexey Proskuryakov
-
Antti Koivisto
-
Gavin Peters (蓋文彼德斯)
-
Maciej Stachowiak