- From: Leif Halvard Silli <lhs@malform.no>
- Date: Tue, 17 Feb 2009 04:29:20 +0100
- To: Steven Faulkner <faulkner.steve@gmail.com>
- CC: Dan Connolly <connolly@w3.org>, "Gregory J. Rosmaita" <oedipus@hicom.net>, HTML WG <public-html@w3.org>, Matt Morgan-May <mattmay@adobe.com>
Steven Faulkner 2009-02-13 18.26: > Hi dan , > in yesterdays HTML WG telecon you were questioning Gregory's idea of > @summary being a long descriptor and wondering where it came from: > > "Each table may have an associated caption (see the CAPTION element) > that provides a short description of the table's purpose. A longer > description may also be provided (via the summary attribute) for > the benefit of people using speech or Braille-based user agents." So HTML 4 sees @summary as "long <caption>". Wheras WCAG 2, per Matt Morgan-May, view @summary as "not any <caption> at all": [1] "The Techniques for WCAG 2 specify that <caption> and @summary should not duplicate one another. [...] It's also not intended to be visible, because it's intended as metadata to describe the structure of the table. Requiring it to be visible makes as much sense as making @alt visible." It is easier to understand why it makes no sense to make @summary visible if we consider it as a long <caption>: It makes sense to render only one <caption>. That way @summary also becomes directly comparable to HTML 4's abbr attribute: Where @summary provides long <caption>, @abbr provides a caption like version of the header cell[2]. Even if @abbr is also intended for visual UAs (small screens anyone?), both attributes provide a longer/shorter version of another element, for the purpose of serving different media types better. As to the argument that if @summary is any useful, then it is also useful for sighted users: This might indeed be the case, and through DOM scripting, it is possible to make the content of any attribute visible. But as @abbr shows: It is also a useful to keep things short. Following Ian's advice to give feedback in the form "as defined, I can't do this with HTML5"[3]: Both <caption> and @summary provides metadata. But currently, in HTML 5, one cannot author the table metadata with both screen readers and visual media in mind, simply because, in visual medias, a long and wordy caption would not work or serve its purpose as caption. Such <caption>s would not even work for screen readers, since those readers too need short, clue giving captions. (As soon as one learns what a particular table is about, the @summary looses more if its purpose, while the short <caption> increases its usefullness.) Thus, HTML 5 as defined does not let us provide users with fast accessed and fast read summaries of tables for the situations when the <caption> does not give the reader enough clue about what the table is about, when starting to wade through the table itself to find this out, would be considerably more timeconsuming than reading a such description. HTML 5, as defined, also does not ofer any way for providing any such table spesific metatada *without* also adding a <caption>. (Authors may feel that not all tables *needs* a any <caption>. However, non-visual media users could benefit from a summary function even in those cases.) Strictly speaking, a summary feature could be useful for all media types, if there were a cross-media method for providing it. Perhaps as a <summary> child element of <caption>? However, then one would need tom make <caption> a required element. See testcase for <summary> inside <caption> in Live DOM viewer. [4] [1] http://www.w3.org/mid/C5AE130E.14131%25mattmay@adobe.com [2] http://www.w3.org/TR/html401/struct/tables.html#adef-abbr [3] http://lists.w3.org/Archives/Public/public-html/2008Dec/0175.html [4] http://tinyurl.com/tableWithSummaryElement -- leif halvlard silli
Received on Tuesday, 17 February 2009 03:30:08 UTC