Subject: Re: Fw: [docbook-apps] Namespace issues with titlepage templates in slides
On Friday, May 10, 2013 06:01:22 PM Jirka Kosek wrote:
> On 8.5.2013 7:19, Bob Stayton wrote:
> > Would have time to take a look at this? It seems Alexey spent a
> > great deal of time sorting out the namespace issues for the DocBook
> > titlepage template system, and has proposed many improvements. As
> > far as I can tell, they make sense, but I think you should look at
> > it.
> Sure, I originally skipped message as from subject line I got impression
> it's related to slides only.
Sorry for a confusing title. This originated as a narrow fix for slides templates, but, through that notorious "let's-fix-one-more-issue" approach quickly evolved into a rework of namespace handling.
> > This issue, however, shows that the titlepage.xsl is not not fully
> > namespace aware. First, it shouldn't "autoguess" the namespace for
> > t:wrapper - instead, it should just discover the namespace referred
> > to by the t:wrapper attribute.
> Autoguessing is here just for backward compatibility. Ideally namespace
> should be passed by ns parameter. Problems you have seen in slides
> titlepages are caused by missing ns parameter in the build script.
I agree that the problem was the slides templates were incorrectly generated - I stated so in my original email. However, my point is that target namespace can be precisely determined by checking the namespace declaration for the wrapper element; this approach works even if that element has no namespace declaration (as in HTML).
> > Attached patches deal with these issues:
> Thanks for the patches. There are many good ideas in your code, but I'm
> little bit worried about backward compatibility -- in past we have tried
> very hard to keep old titlepage templates to work with newer versions of
> stylesheets. I'm not sure whether this is still true with all your
> proposed changes.
Unfortunately, it is not possible to fix the issues with namespace while fully preserving backwards compatibility: as I mentioned in the original email, the problem is that some of the current templates use the default namespace for elements from different XML vocabularies: for example, XHTML and DocBook:
As you see, this template uses default namespace for title/subtitle (DocBook elements) as well as hr (XHTML element).
> Also what's not clear to me is whether your patch will work with non-ns
> version of stylesheets which is primarily targeted for DocBook V4.x.
> Your code has several tests for DocBook namespace which suggests that
> you target only ns version of stylesheets.
Indeed, I do. I thought that docbook-xsl and docbook-xsl-ns are separate packages, isn't it so?
If it is not the case, could you explain which one is considered "master" distribution, ns-aware or non-ns version? And how one is produced from the other? I could probably modify the stylesheet to account for that case as well.
> For example how titlepage will look like for for HTML (not XHTML, so no
> namespace) for non-ns stylesheets (DocBook V4.x, again no namespace)?
Right now it would fail with the following message:
t:titlepage-content contains elements in non-DocBook namespace
(which is an attempt to fail gracefully rather than misinterpreting a non-ns aware template)
Then, if template has DocBook 5.0 namespace declared, it would generate a titlepage.template.xsl with DocBook elements being in a 5.0 namespace. Non-ns variant could probably be accommodated, though - see the questions above.