Re: DOCBOOK: Linking in DocBook V5.0

[Jirka Kosek <jirka@kosek.cz>]

Norman Walsh wrote:

> Given a PE like this:
> 
> <!ENTITY % xlink-optional-simple-link "
>    xlink:type      (simple)        #IMPLIED

I think that there should be #FIXED "simple", so one is not forced to
add xlink:type="simple" to every start tag with link. This will save
typing, but make all instances of particular element simple link. I'm
not sure if this is problem, XLink spec. is quite vague in this topic:

"It is not an error for a simple-type element to have no locator (href)
attribute value. If a value is not provided, the link is simply
untraversable. Such a link may still be useful, for example, to
associate properties with the resource by means of XLink attributes."

> One outstanding problem is the link attribute names. Unfortunately,
> XLink doesn't allow the XLink HREF attribute to be renamed, so we'll
> have to battle the linkend vs xlink:href problem. I think we have
> two options, we could:

If there is a way to rename xlink:href in XLink I would say, adopt it
immediately. Currently I'm not a big fan of adding XLink to DocBook
because we must rename linkend to xlink:href.
 
> 1. Switch. Remove linkend and break everything all at once.

This is not good approach, IMHO.

> 2. Allow both in V5 and remove linkend in V6. Stipulating that when both
>    are present linkend wins (or xlink:href wins, whichever).

In that case, I'm almost sure that linkend will win and we only shift
decision of removing it one DocBook version forward. In this light,
removing linkend in DocBook 5 doesn't sound silly.
 
> For extended links, I'm not sure what makes the most sense. We could
> add new elements, extendedlink, linktitle, linkresource, linklocator,
> and linkarc. Or we could say that extended links must be out-of-line.
> Or perhaps we could do something else. Suggestions?

Is there anybody who need to use extended links? If there is no stress
of adding it to DocBook, I suggest not support it in any way (I can't
imagine how this should be handled in stylesheets). If someone needs
this functionality, he can use out-of-line links (aren't they called
third-party in XLink rec.?), or use namespaced element to add these
links to DocBook document. 

But overall, your proposal sounds very reasonably for me.

			Jirka 

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  Jirka Kosek  	                     
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