- From: Ian B. Jacobs <ij@w3.org>
- Date: Fri, 04 Jan 2002 12:40:19 -0500
- To: rayw@netscape.com, plh@w3.org, lehors@us.ibm.com, shane@aptest.com, gleng@freedomscientific.com, jongund@uiuc.edu, charles@w3.org, asgilman@iamdigex.net
- CC: w3c-wai-ua@w3.org
Hello, Thank you to all who attended the 20 Dec 2001 UAWG teleconf [1] on events, the DOM, and UA requirements. I found it very helpful. The next meeting to resolve open issues will be 17 Jan 2002 @ 4pm ET (telephone: +1-617-252-1038) for up to 90 minutes. At the 20 December meeting, we reviewed a summary [2] of what seemed to be the open issues. Here's the latest summary of where I think we are (and what we have to address on 20 Dec). If I've made technical errors below, please send corrections. Also, please indicate whether there are other issues that I have omitted. Thank you, - Ian 1) What's the best way to ensure that assistive technologies can identify and trigger event handlers? Agreement: A boolean function will suffice; we don't need the list of event handlers. Agreement: We do not need to fire handlers one at a time; it suffices to be able to fire all handlers for a given event type. Open: Should there be one or two boolean functions for querying a node N: a) Does N itself have a handler for event type E? b) Is there *any* observer with a handler for event type E that will be called if E occurs at N? Agreement: In (b), because an observer may stop the capture or bubbling processing phases, node N's handlers may never be invoked if E occurs at N. We may know some behavior in advance from markup (cf. XML events draft [3], 'propagate' attribute). Ray Whitmer has argued that the granularity of the query and the granularity of the dispatch should be the same. If version (a) of the query is chosen, then the query granularity will be one node only, but a dispatch will cause processing by other nodes as well. Thus (if I understand it), Ray prefers version (b) and asked us to provide a use case for version (a): when would an AT need to know that there's a handler on a given node N, even if that node's handlers might not be triggered (if an observer stops the bubble or capture process). Todo: The WAI groups need to provide a use case of when it's useful to know that an event handler was declared on the current node and not an ancestor. 2) What's the best place to describe the semantics of author-specified behaviors? We have not progressed much on this issue. However, there is some sense that this is more of a format issue than a DOM issue. Ray has stated that it doesn't make sense to be able to specify descriptions on a per-handler basis if you can't activate handlers individually. Question: Would it be useful for the DOM to provide all descriptions of all handlers for a given event type? Or should we specify instead (one or more) descriptions for an event type (rather than handler)? Please indicate what other questions WAI or the DOM WG or the HTML WG should answer. [1] http://lists.w3.org/Archives/Public/w3c-wai-ua/2001OctDec/0135 [2] http://lists.w3.org/Archives/Public/w3c-wai-ua/2001OctDec/0132 [3] http://www.w3.org/TR/xml-events/ -- Ian Jacobs (ij@w3.org) http://www.w3.org/People/Jacobs Tel: +1 718 260-9447
Received on Friday, 4 January 2002 12:40:32 UTC