|Lofton Henderson||Apr 27, 2005 7:10 am|
|Benoit Bezaire||Apr 27, 2005 8:53 am|
|Lofton Henderson||Apr 27, 2005 9:29 am|
|Dieter Weidenbruck||Apr 27, 2005 9:49 am|
|Lofton Henderson||Apr 27, 2005 11:13 am|
|Benoit Bezaire||Apr 27, 2005 12:02 pm|
|Benoit Bezaire||Apr 27, 2005 12:36 pm|
|Dieter Weidenbruck||Apr 27, 2005 1:09 pm|
|Benoit Bezaire||Apr 27, 2005 1:59 pm|
|Dieter Weidenbruck||Apr 27, 2005 2:10 pm|
|Lofton Henderson||Apr 27, 2005 2:59 pm|
|Benoit Bezaire||Apr 28, 2005 6:09 am|
|Subject:||Re: [cgmo-webcgm] ISSUE: what does 'get..' return?|
|From:||Benoit Bezaire (ben...@itedo.com)|
|Date:||Apr 28, 2005 6:09:44 am|
Wednesday, April 27, 2005, 5:11:26 PM, Dieter wrote:
DW> Hi Benoit,
BB>> DW> interactivity/visibility/inheritance: BB>> LH>> It seems to me that we're potentially talking about two BB>> LH>> different things: BB>> LH>> first, the Document Object -- a tree that is initially defined BB>> LH>> according to BB>> LH>> DOM rules by data that occurs in the WebCGM document instance BB>> LH>> (+ XCF); and BB>> LH>> second, a "viewer object", which tells us not about the WebCGM BB>> LH>> document but BB>> LH>> about the viewed picture. BB>> DW> IMO, a DOM get call does not return the state found in the document, BB>> DW> it will return the current state. BB>> DW> Example: BB>> DW> A WebCGM is read in to memory, then an XML companion file is used to BB>> DW> set visibility. Of course you want to know about the BB>> current state of BB>> DW> the visibility when doing a get. BB>> DW> Or: BB>> DW> an APS is read without a viewcontext. A set call is used to BB>> set one on BB>> DW> the APS. A subsequent get would retrieve this set BB>> viewcontext, not the BB>> DW> state found in the WebCGM. BB>> The functionality that is defined in the spec does handle both of BB>> those cases. It is returning the current state, but the 'specified' BB>> current state, not the 'computed' (i.e., inherited) current state. DW> I agree that we need the current state, not the computed one. DW> The current state for me, however, is not "undefined", it is "inherit" Lofton came up with "undefined", I didn't. I say (like it is written in the spec today), that the returned value is an empty string.
BB>> DW>> So the "get" on myObj2 would give you an "undefined" BB>> according to your BB>> DW>> suggestion. However, according to the inheritance rules, the actual BB>> DW>> behavior is off as inherited from myObj1. BB>> DW>> So the behavior is not undefined, just the attribute is not there. BB>> DW>> Shouldn't we return "inherit" in such a case? BB>> BB>>Good question... but if we look at other existing BB>> technologies that do BB>> BB>>use inheritance, say HTML and SVG; the answer would be no, an empty BB>> BB>>string is returned. BB>> DW> So in this case we should still have a value "inherit", BB>> because that is BB>> DW> the actual value. Both on or off are explicit behaviors, BB>> inherit is an BB>> DW> explicit behavior to inherit from ancestors. BB>> BB>> DW> I am also thinking about the following case: BB>> BB>> DW> BEGAPS 'first' BB>> DW> 'visibility' off BB>> DW> BEGAPS 'second' BB>> DW> 'visibility' on BB>> DW> ENDAPS; BB>> DW> ENDAPS; BB>> BB>> DW> now I want to set visibility on "second" to inherit. It is BB>> not possible BB>> DW> to do so as there is no explicit value. I could only delete BB>> the attribute. BB>> At the moment, yes, the only way is to remove the attribute. Is this BB>> not sufficient? DW> I could live with this.
DW> The issue for me is the following: DW> The spec says, as quoted from 188.8.131.52: DW> Initial value: on DW> Applies to: layer, grobject, para, subpara DW> Inherited: yes
DW> However, the value that is returned by the DOM get call, is not on. DW> The value is not "on", it is "inherit". That's all we can say about DW> this particular APS without looking at the ancestors. That's correct.
DW> I take it that "inherit" on the root element means "on" I think so too, but I couldn't find that particular explanation in the CSS spec. I'll have to dig some more.
DW> So the spec says, that the value may be inherited: DW> "Inherited: yes" DW> however, it does not spell out how to do this on the APS. I think it does: 184.108.40.206 Specified values
DW> So the wording could be changed in two ways: DW> 1. add verbiage explaining that "no attribute on APS" means "inherit", or Yes.
DW> 2. add "inherit" as a legal value Well adding "inherit" as a legal value doesn't imply that a DOM call would return that value. A DOM call returns the value of a 'specified' attribute. Unless an authoring tool is explicitely setting 'visibility' to 'inherit'; a DOM call should return "on" | "off" or "" (empty string).
DW> Am I overcomplicating this? No.
-- Benoit mailto:ben...@itedo.com