On Mar 2, 2010, at 2:59 AM, Julian Reschke wrote:
Hi,
it appears to me that this header replicates something that is
already there; just use the last event ID as etag, and then you can
do something like:
GET /foobar HTTP/1.1
If-None-Match: "abc"
Note that this makes If-None-Match a request header on which the
response varies, thus it should carry:
Vary: If-None-Match
...but this is the case for Last-Event-ID as well.
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.
- If-None-Match does a conditional GET. But a 304 response to an
EventSource request would not make sense under any circumstances. The
server should wait until it has more events to send, not tell the
client to consult a cached copy. The client likely won't even have a
cached copy.
Regards,
Maciej
