Some notes from my reading of the Pubsubhubbub Draft 0.2 spec: --- Changes Section
Could you add a "Changes" section to the top of the document while it is in draft? Or is there a change list besides svn somewhere? --- Section 5. Discovery I'm confused about "Subscribers MUST NOT use the original URL from before following HTTP redirects to fetch the feed. This is crucial for subscribers to detect feed moves." The spec says: "Per the Atom spec, the //atom:feed/li...@rel="self"] element MUST indicate the topic URL for the original event stream. Subscribers MUST use the self link when requesting a subscription from the hub. Subscribers MUST NOT use the original URL from before following HTTP redirects to fetch the feed. This is crucial for subscribers to detect feed moves." I see that support for redirected feeds is discussed here <http:// code.google.com/p/pubsubhubbub/wiki/MovingFeedsOrChangingHubs>. In the case that I, as a subscriber, do not follow the redirects for the self link, and also in the edge case where it is only just as I've started the subscription process that the publisher decides to add a redirect, what should happen? 1. The hub checks the feed, sees I've used a URL that's now a redirect, and sends me an error. OR 2. The hub checks the feed, sees I've used a URL that's now a redirect, goes ahead and subscribes me as normal anyways, but then uses the Moving Feed protocol to migrate the me to the new location (as per Moving Feeds step 6) on the first ping update. If case 2, maybe should the spec should just say: "For optimal performance, and to avoid involving the feed moving protocol, subscribers SHOULD make sure they have the latest topic URL by checking for redirects on the self link, and if found, should reload that feed and use the new self link therein as the topic URL."? If case 1, on the other hand, we have edge case where someone is subscribing just as the redirect is being added by the publisher. What kind of error would this result in so the subscriber would know how to retry? Does this make sense, or am I misunderstanding something? How is subscribing only with the terminal URL (after redirects) "crucial" to detecting feed moves? Maybe that would clear it up for me. --- Section 6.1.1 Subscription Parameter Details "The topic and callback URLs MUST not contain an anchor fragment." Should this say "MUST NOT" instead of "MUST not"? Cheers, Mason
