W3C home > Mailing lists > Public > public-webapps@w3.org > January to March 2010

Re: Last-Event-ID in http://dev.w3.org/html5/eventsource/

From: Julian Reschke <julian.reschke@gmx.de>
Date: Tue, 02 Mar 2010 19:22:53 +0100
Message-ID: <4B8D577D.6060501@gmx.de>
To: Maciej Stachowiak <mjs@apple.com>
CC: "public-webapps@w3.org" <public-webapps@w3.org>
On 02.03.2010 19:11, Maciej Stachowiak wrote:
>
> On Mar 2, 2010, at 4:07 AM, Julian Reschke wrote:
>
>> On 02.03.2010 12:53, Maciej Stachowiak wrote:
>>> Using If-None-Match this way seems like a bad fit in a couple of ways:
>>>
>>> - Event IDs are not ETags at the HTTP level. It seems like a layering
>>> violation to treat event IDs, or indeed anything in the response body
>>> rather than in the ETag header, as entity tags.
>>
>> Event IDs *could* be used as ETags, in which case there wouldn't be a
>> layering violation.
>
> How? The ETag is sent before the first event, as part of the HTTP
> headers. The server can't know the last event it will send, if the event
> stream is dynamically generated.
> ...

Actually, it could (using Trailers), but I wasn't going to suggest 
something radical like that :-).

So yes, you are right, equating the ETag with the Event-ID doesn't work.

Best regards, Julian
Received on Tuesday, 2 March 2010 18:23:40 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 18:49:37 GMT