- From: Maciej Stachowiak <mjs@apple.com>
- Date: Tue, 20 Apr 2010 04:05:12 -0700
- To: "Tab Atkins Jr." <jackalmage@gmail.com>
- Cc: Sam Ruby <rubys@intertwingly.net>, Ian Hickson <ian@hixie.ch>, Edward O'Connor <hober0@gmail.com>, Julian Reschke <julian.reschke@gmx.de>, "public-html@w3.org WG" <public-html@w3.org>
On Apr 16, 2010, at 9:40 AM, Tab Atkins Jr. wrote: >> Switching back to co-chair mode.... is there a change proposal that >> captures >> these ideas? From my read, this seems very similar to: >> >> http://lists.w3.org/Archives/Public/public-html/2010Apr/0193.html >> >> Perhaps the change proposal would benefit from the addition of some >> non-normative descriptions of the (hopefully) relatively uncommon >> cases >> where this algorithm will produce suboptimal results, as well as >> guidance >> (namely: add id/bookmark) on how best to avoid those cases? > > Done: Recorded: http://dev.w3.org/html5/status/issue-status.html#ISSUE-086 Thanks, Maciej > > Summary > ------- > > The HTML5 algorithm for turning an HTML page into an Atom feed is > unnecessarily permissive in the generation of entry IDs for the Atom > feed. It uses a SHOULD condition in the "Otherwise" clause for > determining the entry ID, but should instead use a MUST condition. > > > Rationale > --------- > > The Atom spec has a MUST condition in their corresponding text. This > condition is in fact unenforceable in some cases, but we can get > closer to enforcing it without requiring anything unreasonable for > authors or implementors, and so should require such. > > > Details > ------- > > In the section of the HTML5 spec concerning the generation of an Atom > feed from an HTML document (currently section 5.5.3), in the step of > the algorithm detailing how to establish the value of the entry id > (currently step 15.9), change the text following the "Otherwise" > clause to the following: > > " > Let id be a user-agent-defined undereferenceable yet globally unique > valid absolute URL. The same absolute URL must be generated for each > run of this algorithm when given the same input. Let has-alternate be > false. > > Non-normative note: This may result in a single entry producing > different ids, if the contents of the corresponding <article> change > often. This may produce an undesirable user experience in Atom feed > consumers, as the single article may exist multiple times in the feed > as distinct entries. It is recommended that authors ensure that one > of the previous conditions can be met, ensuring a stable id even if > the contents of the article change. > " > > As well, I'm not personally clear whether the "this algorithm" > referred to in the first sentence of the "Otherwise" clause is > referring to the overall "produce a feed from a page" algorithm, or > the "produce an entry for the feed from an appropriate <article>" > sub-algorithm. If the former, the text should be changed to instead > refer to the latter. This will ensure greater stability of the > generated ids when a feed is produced from, for example, a blog front > page where new articles are regularly added and old articles are > removed. > > > Impact > ------ > > * The algorithm for generating entry ids uses the appropriate type of > condition, and has a greater chance of creating a good user > experience, since the generated ids are more likely to be stable. >
Received on Tuesday, 20 April 2010 11:05:48 UTC