Re: SVG12: Cancel events?

* MAHE Vincent RD-TECH-REN wrote:
>I've been given an action to rewrite the example in this section.
>I intend to put an example which shows something like an EPG
>(Program Guide) where after the 5 minutes the navigation order
>is changed using scripting methods.

This sounds very good, thanks much for taking this action!

>Beyond that, you must know that the WG has resolved to add
>stopPropagation() and preventDefault() methods to the uDOM since
>SVGT supports XML Events which <listener> element already supports
>the following attributes : defaultAction="cancel" and propagate="stop".

Okay, then I have some additional comments:

  * prose and schema should allow ev:event, ev:observer, ev:target
    ev:handler, ev:propagate, ev:defaultAction on the relevant elements
  * the ev:listener element should be allowed in prose and schema
  * XML Events should be a normative reference
  * all events should specify whether they are cancelable
  * the user interface events discussion should consider canceling
    events, e.g. 13.4 lacks the note "unless an appropriate action has
    been taken to prevent further processing" that was in SVG 1.1
  * it should be clarified that <ev:listener ev:event = '---' ... />
    is disallowed (http://www.w3.org/mid/40E45DC1.9020603@expway.fr)
  * the examples should be corrected (none of the listener examples
    does what it should)
  * processing of <ev:listener phase="capture"> and use of ev:phase
    should be clarified as SVG Tiny 1.2 does not yet support that
  * it should probably be pointed out why neither isDefaultPrevented()
    nor stopImmediatePropagation() are supported
  * section 14.1.1 should define whether ev:listener may refer to
    external handlers and if so, whether that must be supported or
    is optional as in XML Events Basic Profile
  * ev:listener should probably be added to some module and might
    need a feature string
  * it should be clarified whether ev:listener can have xml:id,
    xml:lang, xml:space, and/or xml:base
  * it should be clarified whether ev:listener may have svg
    content like <svg:desc> 
  * it should be clarified which of the ev:listener and ev:*
    attributes are animatable (if any), that's only defined for
    ev:event at the moment
  * it should be clarified which interfaces ev:listener objects
    implement
  * it should be clarified what happens when the ev:listener element
    is removed from the document
  * ev:listener dependency processing should be clarified, e.g. by
    referring to XML Events 3.6
  * error handling for XML Events errors should be clarified

I originally assumed this is not missing from the document and that
ev:event is the only XML Events feature supported in SVG Tiny 1.2...
There are probably more things that I've missed in the list above,
I would appreciate if someone could point out the changes made to
the draft so I can properly acknowledge the response.

>So if we want to have a better consistency and since we do not want
>to define a subset of XML Events, we have decided to add these 2
>methods() to uDOM, which are certainly not very hard to implement
>(it's easier to cancel or drop an event than to process it right ?).

Perhaps; note though that without support for the capture phase and due
to the various differences between XML Events and XML Events in SVG 1.2,
SVG 1.2 is not a conforming Host Language and SVG Tiny 1.2 user agents
would not be conforming XML Events user agents as defined in XML Events.

Also note that the XML Events integration in XHTML 2.0 as well as the
<handler> element in XHTML 2.0 are quite different from what's in SVG
Tiny 1.2, hopefully that will get looked at before either reaches CR.
-- 
Björn Höhrmann · mailto:bjoern@hoehrmann.de · http://bjoern.hoehrmann.de
Weinh. Str. 22 · Telefon: +49(0)621/4309674 · http://www.bjoernsworld.de
68309 Mannheim · PGP Pub. KeyID: 0xA4357E78 · http://www.websitedev.de/

Received on Saturday, 28 May 2005 04:54:41 UTC