Re: FW: 1.1 WD Comment on autogenerated property IDs.

Thanks for the explanation.  I now see that because
these IDs are unreachable, an implementation need not
bother calculating them, due to the general rule of it
not being necessary to explicitly set the initial
value of every property on every FO.

Glen


--- Paul Grosso <pgrosso@arbortext.com> wrote:

> Forwarding to xsl-editors.
> 
> ________________________________
> 
> From: w3c-xsl-fo-sg-request@w3.org
> [mailto:w3c-xsl-fo-sg-request@w3.org]
> On Behalf Of Steve Zilles
> Sent: Tuesday, 2004 September 28 20:53
> To: Glen Mazza
> Cc: w3c-xsl-fo-sg@w3.org
> Subject: 1.1 WD Comment on autogenerated property
> IDs.
> 
> 
> On Sat, 21 Aug 2004 11:14:02 -0400, Glenn Mazza
> wrote:
> 
> 
> 
> 	Editors:
> 	
> 	I previously wrote [1] on the issue of
> autogenerated property
> ID's a few 
> 	months back.  I have an additional comment on this
> topic and a
> 	change to 
> 	my previous suggestion:
> 	
> 	A search on <idref> within the 1.1 WD gives only
> two defined
> uses
> 	of the 
> 	ID property:
> 	
> 	1.) as the internal_destination for an
> fo:basic-link.
> 	2.) as the ref_id for an fo:page-number-citation.
> 	
> 	If this is correct, then given that both defined
> uses for the
> property 
> 	ID require the user to have advance knowledge of
> what the ID
> value is, 
> 	the value of subsequently autogenerated ID's for
> FO's remains
> 	unclear.  
> 	OTOH, if autogeneration is primarily for internal
> processing of
> the 
> 	document, that would appear to be an implementation
> detail that
> doesn't 
> 	need to be placed in the recommendation.  (FOP, for
> example,
> 	currently 
> 	does not need such an autogenerated ID, and
> shouldn't be
> required to 
> 	generate one.) ...
> 
> Glenn you are correct that the autogenerated ID's
> are not reachable by
> any links (either inside or outside the document).
> In fact, an
> implementation can ignore these IDs. They were put
> into the
> specification to satisfy the following requirements:
> 
> 1) every property must have an initial value.
> 
> 2) the "ID" property takes an identifier (string of
> characters) as its
> value and that string must be unique in the result
> tree.
> 
> Requirement 1) means that some value must be
> specified and requirement
> 2) means that the value cannot be a keyword, such as
> "none" because that
> would be a legal ID identifier. Furthermore, the
> value must be unique in
> the result tree which eliminates any single initial
> value.
> 
> That lead us to the creation of a random unique
> identifier that is
> unique in the result tree. This is effectively
> equivalent to your
> "implementation dependent value", but more clearly
> satisfies the above
> formal requirements of the specification. Therefore,
> the Working Group
> sees no need to make a change in the specification
> nor is there any need
> for an implementation to realize these not reachable
> IDs.
> 
> 
>         Steve
> =====================================
> Steve Zilles 
> 115 Lansberry Court, 
> Los Gatos, CA 95032-4710
> steve@zilles.org 
> 
>

Received on Monday, 4 October 2004 00:13:19 UTC