Re: [docbook] XPath expression for book title

[Thomas Schraitle <tom_schr@web.de>]

Hi Stephen,

On Sonntag, 24. August 2008, Stephen Taylor wrote:
> Looking for an XPath expression that will give me the title of my book.
>
> I want the title element of my book reproduced in the running headers.
> In the header.content template <http://pastebin.com/m424a9b30> in my
> customisation layer I've been trying variations of
>
> <xsl:value-of select="/bookinfo/title"></xsl:value-of>
> <xsl:apply-templates select="/bookinfo/title" />
>
> but get an empty result.

First, from what I've seen, I fear your DocBook5 document is not valid. 
DocBook5 does not have any bookinfo elements anymore. It is replaced with 
info. As a rule of thumb, always validate your document before applying 
any transformations on it. :)

Second, as you have a DocBook5 document, you have to use the respective 
namespace in your stylesheets too. Declare it in your root element, for 
example:

 <xsl:stylesheet version="1.0"
    xmlns:d="http://docbook.org/ns/docbook";
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
   ...
 </xsl:stylesheet>

After this modification, you have to use the declared prefix on all your 
DocBook5 elements:

 <xsl:apply-templates select="d:info/d:title"/>

However, a title can occur not only inside a d:info element, it can occur 
directly after d:book too. Probably it is better to extend the above 
expression like this (if your current context is d:book):

 <xsl:apply-templates select="(d:info/d:title|d:title)[1]"/>

This selects only one of the possible titles, either in d:info or in 
d:book. If you need only the string content of a title regardless of the 
elements inside, replace xsl:apply-templates with xsl:value-of.

This is just a general explanation, maybe you have to play with the 
customization a bit and use other modes. See also Bob's book for more 
information at http://www.sagehill.net/docbookxsl/index.html


> The document is modular: a short master
> document<http://pastebin.com/m6e07225c>includes a series of article
> documents. Is that changing the reference of
> the document root?

I'm not sure what you mean by "changing the reference of the document 
root".


> If so, then 
>
> <xsl:value-of select="/artheader/title"></xsl:value-of>
>
> would yield my article titles in the headers. But that doesn't happen
> either.

Probably the same issue as above.


Hope that helps,
Tom

-- 
Thomas Schraitle