Re: [docbook-apps] Renaming processing instructions

["Bob Stayton" <bobs@sagehill.net>]

Yes, you can use names in the PIs that differ from the output attribute 
names.  In fact, there is no automatic passthrough. The information inside a 
dbfo PI is actually pseudo-attributes.  They look like attributes, but they 
are just text strings organized in a way that can assign a value to a name. 
The PI processing templates parse them as strings to extract a value 
assigned to a given pseudo-attribute name.  Then some template has to 
generate an actual <xsl:attribute> to assign the value to an output 
attribute name, which is independent of the pseudo-attribute name.  So your 
example could be:

A PI in the source file:

<?dbfo bgimage="myfile.jpg"?>

Extracting the value:

<xsl:variable name="bgroundimage">
 <xsl:call-template name="dbfo-attribute">
   <xsl:with-param name="pis"
       select="ancestor-or-self::d:abstract/processing-instruction('dbfo')"/>
   <xsl:with-param name="attribute" select="bgimage"/>
 </xsl:call-template>
</xsl:variable>

<xsl:variable name="backgroundimg">
 <xsl:value-of select="concat('url(', $bgroundimage, ')')"/>
</xsl:variable>

and further down, using the value for an output attribute:

<xsl:attribute name="background-image">
 <xsl:value-of select="$backgroundimg"/>
</xsl:attribute>


Bob Stayton
Sagehill Enterprises
bobs@sagehill.net



From: Xmplar
Sent: Tuesday, October 30, 2012 3:11 AM
To: docbook-apps@lists.oasis-open.org
Subject: [docbook-apps] Renaming processing instructions


I have managed to (mostly) achieve the PIs I need, but I'd like to know if 
it's possible to rename PIs to shorten the amount of text.
In the XML I have:
<abstract>
           <?dbfo background-image="images/Box5-4.gif" 
background-position="0% 30%" ex:background-content-width="60mm"?>
           <title>Chapter 1 overview</title>
...

My customization so far needs to use those long names  ("background-image", 
etc.). Can I somehow rename these to, say, "bgimage" instead of 
"background-image"?

My customization is:
<xsl:template match="d:abstract" mode="chapter.titlepage.recto.auto.mode">

   <xsl:variable name="bgroundimage">
     <xsl:call-template name="dbfo-attribute">
       <xsl:with-param name="pis"
         select="ancestor-or-self::d:abstract/processing-instruction('dbfo')"/>
       <xsl:with-param name="attribute" select="'background-image'"/>
     </xsl:call-template>
   </xsl:variable>
   <xsl:variable name="backgroundimg">
     <xsl:value-of select="concat('url(', $bgroundimage, ')')"/>
   </xsl:variable>

   <xsl:variable name="bgroundwidth">
     <xsl:call-template name="dbfo-attribute">
       <xsl:with-param name="pis"
         select="ancestor-or-self::d:abstract/processing-instruction('dbfo')"/>
       <xsl:with-param name="attribute" 
select="'ex:background-content-width'"/>
     </xsl:call-template>
   </xsl:variable>

   <xsl:variable name="bgroundposition">
     <xsl:call-template name="dbfo-attribute">
       <xsl:with-param name="pis"
         select="ancestor-or-self::d:abstract/processing-instruction('dbfo')"/>
       <xsl:with-param name="attribute" select="'background-position'"/>
     </xsl:call-template>
   </xsl:variable>

   <fo:block xmlns:fo="http://www.w3.org/1999/XSL/Format";
     xmlns:ex="http://www.renderx.com/XSL/Extensions";
     xsl:use-attribute-sets="chapsummaryprops">
     <xsl:if test="processing-instruction()">
       <xsl:attribute name="background-image">
         <xsl:value-of select="$backgroundimg"/>
       </xsl:attribute>
       <xsl:attribute name="ex:background-content-width">
         <xsl:value-of select="$bgroundwidth"/>
       </xsl:attribute>
       <xsl:attribute name="background-position">
         <xsl:value-of select="$bgroundposition"/>
       </xsl:attribute>
     </xsl:if>

     <xsl:apply-templates select="d:title" />
     <xsl:apply-templates select="d:para" />
   </fo:block>
 </xsl:template>

Thanks,

On 29-10-12 10:35 PM, Xmplar wrote:
I'm trying to create a custom processing instruction to insert and format a 
background image in a chapter abstract. I've followed the instructions in 
Chapter 9 of DocBook XSL TDG but am getting error messages about empty 
parameters.
The XML is:
<abstract>
           <?dbfo bgimage="images/Box5-4.gif"?>
           <?dbfo bgposition="50% 30%"?>
           <?dbfo bgwidth="170mm"?>
           <title>Chapter 1 overview</title>
           <para>The text in . </para>
       </abstract>
   </info>
(I'd like to combine all three params into one pi if possible.)

I've set up variables for background-image, content-width and position:
<xsl:template match="d:abstract" mode="chapter.titlepage.recto.auto.mode">
   <xsl:variable name="bgimage">
     <xsl:call-template name="dbfo-attribute">
       <xsl:with-param name="pis"
         select="ancestor-or-self::d:abstract/processing-instruction('dbfo')"/>
       <xsl:with-param name="attribute" select="'background-image'"/>
     </xsl:call-template>
   </xsl:variable>
   <xsl:variable name="bgwidth">
     <xsl:call-template name="dbfo-attribute">
       <xsl:with-param name="pis"
         select="ancestor-or-self::d:abstract/processing-instruction('dbfo')"/>
       <xsl:with-param name="attribute" 
select="'ex:background-content-width'"/>
     </xsl:call-template>
   </xsl:variable>
   <xsl:variable name="bgposition">
     <xsl:call-template name="dbfo-attribute">
       <xsl:with-param name="pis"
         select="ancestor-or-self::d:abstract/processing-instruction('dbfo')"/>
       <xsl:with-param name="attribute" select="'background-position'"/>
     </xsl:call-template>
   </xsl:variable>

   <fo:block xmlns:fo="http://www.w3.org/1999/XSL/Format";
     xmlns:ex="http://www.renderx.com/XSL/Extensions";
     xsl:use-attribute-sets="chapsummaryprops"
     background-image="{$bgimage}"
     ex:background-content-width="{$bgwidth}"
     background-position="{$bgposition}">
     <xsl:apply-templates select="d:title" />
     <xsl:apply-templates select="d:para" />
     <!--<xsl:apply-templates select="." 
mode="chapter.titlepage.recto.mode"/>-->
   </fo:block>
 </xsl:template>

And when I process it with Saxon 6.5.5 the error messages are:
[warning] Attribute 'background-image' cannot have a value of "": should be 
either 'inherit' or a URI: background-image="url(...)".
   [error] Attribute 'rx:background-content-width' cannot have a value of 
"".
I'm using DB 1.77.1, XEP 4.19.
Thanks
--
Dave Gardiner