- From: James Craig <jcraig@apple.com>
- Date: Fri, 21 Feb 2014 16:32:30 -0800
- To: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
- Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>
OFF TOPIC On Feb 21, 2014, at 3:13 PM, Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no> wrote: > When Webkit says ”data table” does it mean the same as the proposed > role=table? > > I ask a) because HTML5 talks about ”non-layout” vs ”layout” and b) > because I myself came to the conclusion that ”non-layout” could be > applied to anything that isn’t ”layout”. Thus, <table role=grid> is a > non-layout table. However, Webkit, while not disagreeing, says that, > quote: > > ”// Do not consider it a data table is it has an ARIA role.” > > First, this rule obviously will not be true once role=table emerges. Keep reading… There is more than that. If it ends up with a grid role it is a data table, but specific implementation details are probably off topic for the general subject of this discussion. I just referenced that file as a starting point. > Second, this means that Webkit categorizes differently from how the > spec categorizes. So, to base anything on Webkit, either the spec must > reinterpret what Webkit does, in order to decide what it means in spec > context. Or that the spec should stop talking about ”non-layout”. > > It seems to me that it would be useful if the spec more aligned itself > with Webkit and thus start speaking about data tables instead of > non-layout table. This will also allow us to speak about non-data > non-layout tables. And thus the spec would become more specific. > > Leif H Silli > > James Craig, Fri, 21 Feb 2014 10:29:36 -0800: >> Just copy what the open source browsers are doing already. For example: >> >> AccessibilityTable::isDataTable() >> > http://trac.webkit.org/browser/trunk/Source/WebCore/accessibility/AccessibilityTable.cpp#L93 >> >> >> On Feb 21, 2014, at 2:19 AM, Leif Halvard Silli wrote: >> >>> After filing bug 24679 [1], which suggests to add more features to the >>> list of ”possible indicators”[2] for layout tables vs non-layout >>> tables, I was asked to provide data for the proposals. But how should >>> one go about providing data? >>> >>> Web data is of what ultimately matters. But when identifying possible >>> indicators, it seems that knowing what features AT actually use for >>> discerning between layout and non-layout tables, would give us a good >>> shortlist of candidate indicators. Secondly, if we can spot some trends >>> in the (hopefully correct) data we already have, then that - as well - >>> could help us identify candidates. >>> >>> Today, its appears possible to glean following trends in the spec: >>> >>> 1) Conformance, completeness amd semantics indicate non-layout >>> usage. The spec lists borders via CSS or @border=1, <th>, >>> <thead>, <caption>, @headers, @scope. >>> 2) Non-conforming ways to disable borders (border=0/cellspacing=0 >>> cellpadding=0) plus role=presentation indicate layout usage. >>> 3) @summary is ”not a good indicator” (this is probably based >>> *both* on Web data *and* AT behavior analysis >>> >>> Trends & AT data applied to: table@border >>> >>> To me, HTML5’s table over “possible indicators” of (non-)layout usage, >>> seems correct, but not complete. However, in bug 24678,[3] Steve asks >>> for data about *one* non-layout indicator, namely border=1. But which >>> data? Web data? Assistive technology data? The fact that VoiceOver + >>> Safari matches spec w.r.t. borders as non-layout indication, ought to >>> put it on the shortlist of non-layout features. In another, somewhat >>> related, bug, Steve indicated that web data did not support that >>> table@border=1 indicates data tables.[4] My own toe dipping into same >>> pool told me the opposite. >>> >>> Trends & AT data applied to: <colgroup> with <col/> children. >>> >>> It seems in line with the conformance & completeness trend that >>> VoiceOver+Safari treats <colgroup> with <col/> children[*] as indicator >>> of non-layout usage. What do other ATs do? What does Web data say? >>> Should the spec change accordingly? (PS: I know one HTML generator >>> which, for layout tables in XHTML1/HTML4, uses cellpadding=0 >>> cellspacing=0, but which for HTML5 removes cellpadding/cellspacing and >>> *adds* <colgroup> with children, with bad results in VoiceOver as >>> result.) >>> >>> Trends & AT data applied to: lack of cellpadding=0 cellspacing=0[*] >>> >>> Is it risky to delete cellpadding=0 cellspacing=0 from a table? >>> Could it cause an AT to treat a layout table, as a non-layout table? >>> This question seems relevant since authors are probably simply deleting >>> these attributes without adding @role=presentation in their place. >>> >>> Trends & AT data applied to: presence of sortable attribute >>> >>> This is good candidate based on its strong link to data tables - it is >>> a semantic feature. But is is also possible to take the view that we >>> need implementation and usage before putting into the spec. >>> >>> Finally: How important are heuristics for identifying data tables? Does >>> the situation remind about how UAs detect quirks vs no-quirks? (Except >>> in XHTML and @srcdocs (other exceptions?), no-quirks is triggered when >>> UAs detect a DOCTYPE that meets certain conformance and completeness >>> criteria.) >>> >>> [1] https://www.w3.org/Bugs/Public/show_bug.cgi?id=24679 >>> [2] >>> > http://www.w3.org/html/wg/drafts/html/master/tabular-data.html#the-table-element >>> [3] https://www.w3.org/Bugs/Public/show_bug.cgi?id=24678 >>> [4] https://www.w3.org/Bugs/Public/show_bug.cgi?id=24647#c7 >>> [*] I did not check omitting <col/> child or omitting parent <colgroup> >>> -- >>> leif halvard silli >>
Received on Saturday, 22 February 2014 00:32:59 UTC