Hi,
I presume your simple document's root element has the namespace declaration
xmlns="http://docbook.org/ns/docbook", and
that you are using the docbook-xsl-ns namespace aware stylesheets,
correct?
A1: The preferred way is with xsl:apply-templates in most cases. That
way any child elements are processed with their templates. When you use
xsl:value-of, it returns only the text strings within the element, ignoring any
element markup, and you lose such things as subscript positioning and
generated trademarks.
There are a few situations where you must have text only, such as when you
are computing an attribute value such as alt which cannot contain markup
elements. Even then, I usually use apply-templates inside a variable, and
then take the value-of of the variable. That way any generated text is
included.
Back to your question, many of the elements in info don't have templates in
the default mode (no mode), only in mode="titlepage.mode". That is the case with
releaseinfo. Fortunately, the titlepage.mode works outside of titlepages
too when it is applied. You could also create a new template in a new mode, such
as mode="footer.mode", and apply that mode if you need different behavior.
A2: The date element does have a template in default mode, in
fo/inline.xsl. I think that's because date also appears in revhistory, and
revhistory can appear in lots of places outside of titlepages.
A3: The default mode is generally used to process the content of a document
in document order. But info is one of those elements that contains metadata, and
is generally not meant to be processed in document order. The titlepage spec
file exists to rearrange or omit elements in info. The default mode
template for info is empty to prevent it from being accidentally processed in
document order:
<xsl:template
match="d:book/d:info"></xsl:template>
Modes are used to process elements outside of document order, such as in a
toc and titlepage.
A4: answered in Q1.
A5: The difference is the context from which the template is applied.
The titlepage and toc are generated by the template with match="d:book", so the
current context element is <book>, and so a relative path such as
"d:info/d:releaseinfo" works relative to that context. A chapter is
generated by the template with match="d:chapter", so the current context
elements is <chapter>, and now a path relative to the chapter would look
for d:chapter/d:info, which probably doesn't exist in your document.
To get at the book's info element from all contexts, you need a full
XPath:
select="/d:book/d:info/d:releaseinfo
Hope this helps.
Bob Stayton
Sagehill Enterprises
----- Original Message -----
From:
Damon
Mannion
To:
Sent: Friday, May 08, 2009 6:58 AM
Subject: [docbook-apps] trouble with
footers
Hi
Some newbie questions below. I have been battling with getting the
document info elements working in the footer, and have hit a number of
dead-ends. I suspect my questions and all related, and my lack of
understanding underpins them all.
I have a simple document:
<book>
<info>
<date>2009-03-29</date>
<releaseinfo><trademark
class="registered">CompanyName</trademark> Ltd 2009, all rights
reserved.</releaseinfo>
and want parts of the document info elements to appear in the footer,
so:
<xsl:when test="$position = 'left'">
<xsl:value-of select="d:info/d:date"/>
<fo:block/>
<xsl:apply-templates
select="d:info/d:date"/>
</xsl:when>
Q1 - which is the preferred way of doing this, value-of or
apply-templates?
However, when I pull into the release info into the footer using
apply-templates, I get the following compile error:
"Element releaseinfo in namespace 'http://docbook.org/ns/docbook'
encountered in info, but no template matches."
I can get around this by specifying a mode parameter, but I am not sure
what mode to be setting.
Q2 - why does releaseinfo behave differently to date?
Q3 - if apply-templates is the right way of doing this, then should there
be a mode setting, if so what/why?
Then something strange happens with how the releaseinfo is displayed,
with this setup in the footer:
<xsl:apply-templates
select="d:info/d:releaseinfo"/>
<fo:block/>
<xsl:value-of select="d:info/d:releaseinfo"/>
The apply-templates line produces this output:
"<releaseinfo>CompanyName® Ltd 2009, all rights
reserved.</releaseinfo>"
and the value-of produces this output:
"CompanyName Ltd 2009, all rights reserved."
Q4 - why does the value-of lose the registered trademark?
Finally, the footer output for date and releaseinfo appear on the
titlepage and toc, but as soon as the main body of the document (i.e. chapter
1 on) starts, the output from date and releaseinfo do not appear in the footer
at all.
Q5 - why does the behaviour change at the point, and how to
resolve?
Thanks for any help/pointers.
Damon
