RE: [dita] Why There are Constraints on Conref

["Ogden, Jeff" <jogden@ptc.com>]

I've been using the terms "source" and "target" in just the opposite
way, but I don't think there is a right and a wrong here. I'm not sure
what terms to use to avoid ambiguity.

   -Jeff

> -----Original Message-----
> From: Tony Self [mailto:tself@hyperwrite.com]
> Sent: Tuesday, September 29, 2009 8:19 PM
> To: Ogden, Jeff; 'dita'
> Subject: RE: [dita] Why There are Constraints on Conref
> 
> Thanks for the clarification, Jeff.
> 
> With regard to the terms "conref source" and "conref target", I have
> been
> using "conref source" to mean the element containing the content to be
> re-used (with an id attribute), and "conref target" to mean the
element
> into
> which the content source is included (with a conref attribute). Am I
> using
> the terms the wrong way round?
> 
> Cheers
> 
> Tony
> 
> -----Original Message-----
> From: Ogden, Jeff [mailto:jogden@ptc.com]
> Sent: Tuesday, 29 September 2009 11:35 PM
> To: tself@hyperwrite.com; dita
> Subject: RE: [dita] Why There are Constraints on Conref
> 
> Tony,
> 
> I think the description in your message is correct.  In another
message
> Rob said that you had things reversed, but I think the problem is just
> some ambiguity in the wording so that it isn't completely clear what
is
> the conref source and what is the conref target.
> 
> In the html file you attached there is an example of how constraints
> are
> declared using @constraints and @constraints-scope, but I think that
> approach is obsolete and has been replaced with a declaration that is
> part of @domains.
> 
> Your html file also says that you can add and remove attributes, but
> I'm
> pretty sure you can only remove attributes using constraints.
> 
> And as Rob says, the reason that you can't just test to see if the
> conref material is legal based on the DTD or XSD is that test would be
> based upon the content in a particular conref target document instance
> at a particular time and at a different time the same conref target
> document might be different and might be invalid.  The current conref
> validation scheme gives you a guarantee that what is a valid conref
> will
> remain valid into the future.  This guarantee comes at the expense of
a
> more restrictive policy then is absolutely necessary under some
> circumstances.  But the restrictive policy is very similar to the
> policy
> that has existed for a long time with respect to conref and domains
and
> as far as I know that hasn't been a serious problem.
> 
>    -Jeff
> 
>