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
[email protected]
----- Original Message -----
From: Damon Mannion
To: [email protected]
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
