541032 - aria-describedby doesn't work when targeting table or th element in FF3.6

Status: RESOLVED WORKSFORME

(Core :: Disability Access APIs, defect)

Description

[Hans Hillen]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6

When using aria-describedby to reference a table element, the table's contents are not added as MSAA description.


Reproducible: Always

Steps to Reproduce:
1. Open the attached html file in FF 3.6 
2. Use inspect32 another MSAA checker to inspect the two div elements marked up as ARIA buttons ('button 1' and 'button 2'). Both of these buttons reference the 'descTable' element using the aria-describedby attribute.
Actual Results:  
The textual contents from the 'descTable' are not included in the accessible descriptions of the ARIA Buttons.  

Expected Results:  
Both buttons should include the table text ("hello this is a table used as description") in their MSAA description

Issue didn't occur in 3.5. I know that tables aren't recommended for descriptions, but there are some use cases for it.

Comment 1

[Hans Hillen]

Attachment: test case

Comment 2

[Marco Zehe (:MarcoZ)]

Also confirmed in Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.3a1pre) Gecko/20100119 Minefield/3.7a1pre (.NET CLR 3.5.30729)

Comment 3

[Marco Zehe (:MarcoZ)]

This sounds similar to bug 526915 where we should mayb ecalculate the name from subtree if requested.

Comment 4

[Marco Zehe (:MarcoZ)]

More comments: In Minefield, neither description does work, in Firefox 3.6, the one on "Button1", marked up with a div with role "presentation" does work. So we have two different regressions, with one being only in Firefox 3.6 (the one pointing to the table), and the other one being in Minefield (neither description works).

Comment 5

[alexander :surkov (:asurkov)]

I'm kind of septic to calculate the accessible name or description from the table subtree. It would be nice to see real usecase of this.

Concerning to accessible name/description calculation from presentation node I find this reasonable. But we need a different bug for this I think.

Comment 6

[Hans Hillen]

My use case is Firebug's Net panel, which consists of a keyboard navigable grid. When certain cells in the grid are hovered over or focused, more specific details related to the cell's value appear next to it.These details are structure in a  table element. To make the floating information perceivable by screen reader users, I also reference the table containing the cell details using aria-describedby. The accessible description is then a linearized version of the tabular data. To illustrate, I'll attach a screenshot.

Comment 7

[Hans Hillen]

Attachment: Screenshot of Firebug's Net panel, showing a highlighted cell that references a floating details table using aria-describedby

Comment 8

[alexander :surkov (:asurkov)]

(In reply to comment #6)
> My use case is Firebug's Net panel, which consists of a keyboard navigable
> grid. When certain cells in the grid are hovered over or focused, more specific
> details related to the cell's value appear next to it.These details are
> structure in a  table element. To make the floating information perceivable by
> screen reader users, I also reference the table containing the cell details
> using aria-describedby. The accessible description is then a linearized version
> of the tabular data. To illustrate, I'll attach a screenshot.

Does it comfortable enough for AT users? Should AT be notified the tooltip appears on the screen so that AT user can navigate through the table inside of tooltip and get needed information?

Marco, what do you think?

Comment 9

[Marco Zehe (:MarcoZ)]

Hans, is that table that has the additional information only a table for layout reasons, or would the user gain anything by actually being able to naivgate that information (for example by right-arrowing into that table)?

I'd in principle be fine with the approach Hans is taking here if keyboard-navigating that additional information doesn't really improve readability.

Comment 10

[Hans Hillen]

The table in question is technically speaking a small, headerless data table. So Surkov is right in suggesting it should be navigable that way. I'll just have to figure out how to achieve that keyboard wise, since the Net panel's interface is already quite complex the way it is. Having said that, I suppose it's reasonable to not support tables to be targeted with aria-describedby. The only use case would be referencing layout tables, but in that scenario the issue could  be solved by giving the table a role of "presentation". So I suppose this bug can be discarded.

Comment 11

[alexander :surkov (:asurkov)]

wontfix per comment #10

Comment 12

[Hans Hillen]

My colleague noticed that referencing TH elements with either aria-labelledby or aria-describedby doesn't work either, so that definitely needs to be fixed. It should be possible to use table header elements as description for cells in complex data tables using aria-describedby.

Comment 13

[David Bolter [:davidb] (NeedInfo me for attention)]

(In reply to comment #12)
> My colleague noticed that referencing TH elements with either aria-labelledby
> or aria-describedby doesn't work either, so that definitely needs to be fixed.
> It should be possible to use table header elements as description for cells in
> complex data tables using aria-describedby.

I think Alexander is probably best to respond to this. For regular tables it would seem redundant to add the describedby relation for the header, but in the case of complex tables I'm not sure.

Comment 14

[David Bolter [:davidb] (NeedInfo me for attention)]

Could you provide an example case of where/how you would like to reference TH via describedby?

Comment 15

[alexander :surkov (:asurkov)]

Btw, it should be working. I mean we don't deny this and the accessible name of row and column headers are calculated from subtree. It should be something wrong with code logic.

Comment 16

[alexander :surkov (:asurkov)]

Hans, can you give a testcase for comment #12 please?

Comment 17

[alexander :surkov (:asurkov)]

Hans, ping?

Comment 18

[James Teh [:Jamie]]

The td and the button both get descriptions in this test case:
data:text/html,<table id="table"><tr><th id="th">th</th><td aria-describedby="th">td</td></tr></table><button aria-describedby="table">button