Customizing PDF output

You can build a DITA-OT plug-in that contains a customized PDF transformation.

This topic demonstrates the process of building a plug-in (com.example.print-pdf) that creates a new transformation type: print-pdf. The print-pdf transformation has the following characteristics:

• Uses A4 paper
• Renders figures with a title at the top and a description at the bottom

• Use em dashes as the symbols for unordered lists

• In the plugins directory, create a directory named com.example.print-pdf.

• In the new com.example.print-pdf directory, create a plug-in configuration file (plugin.xml) that declares the new print-pdf transformation and its dependencies.

  <?xml version='1.0' encoding='UTF-8'?>
  <plugin id="com.example.print-pdf">
   <require plugin="org.dita.pdf2"/>
   <feature extension="dita.conductor.transtype.check" value="print-pdf"/>
   <feature extension="dita.transtype.print" value="print-pdf"/>
   <feature extension="dita.conductor.target.relative" file="integrator.xml"/>
  </plugin>
  

• Add an Ant script (integrator.xml) to define the transformation type.

  <?xml version='1.0' encoding='UTF-8'?>
  <project name="com.example.print-pdf">
   <target name="dita2print-pdf.init">
     <property name="customization.dir" location="${dita.plugin.com.example.print-pdf.dir}/cfg"/>
   </target>
   <target name="dita2print-pdf" depends="dita2print-pdf.init, dita2pdf2"/>
  </project>
  

• In the new plug-in directory, add a cfg/catalog.xml file that specifies the custom XSLT style sheets.

  <?xml version="1.0" encoding="UTF-8"?>
  <catalog prefer="system" xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
   <uri name="cfg:fo/attrs/custom.xsl" uri="fo/attrs/custom.xsl"/>
   <uri name="cfg:fo/xsl/custom.xsl" uri="fo/xsl/custom.xsl"/>
  </catalog>
  

• Create the cfg/fo/attrs/custom.xsl file, and add attribute and variable overrides to it. For example, add the content highlighted with bold to change the page size to A4.

  <?xml version="1.0" encoding="UTF-8"?>
  <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                 version="2.0">
  ** <!-- Change page size to A4 --\>
   <xsl:variable name="page-width"\>210mm</xsl:variable\>
   <xsl:variable name="page-height"\>297mm</xsl:variable\>**
  </xsl:stylesheet>
  

• Create the cfg/fo/xsl/custom.xsl file, and add XSLT overrides to it. For example, the following code changes the rendering of elements.

  <?xml version="1.0" encoding="UTF-8"?>
  <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                 xmlns:xs="http://www.w3.org/2001/XMLSchema"
                 xmlns:fo="http://www.w3.org/1999/XSL/Format"
                 version="2.0">
   <!-- Move figure title to top and description to bottom -->
   <xsl:template match="*[contains(@class,' topic/fig ')]">
     <fo:block xsl:use-attribute-sets="fig">
       <xsl:call-template name="commonattributes"/>
       <xsl:if test="not(@id)">
         <xsl:attribute name="id">
           <xsl:call-template name="get-id"/>
         </xsl:attribute>
       </xsl:if>
       <xsl:apply-templates select="*[contains(@class,' topic/title ')]"/>
       <xsl:apply-templates select="*[not(contains(@class,' topic/title ') or contains(@class,' topic/desc '))]"/>
       <xsl:apply-templates select="*[contains(@class,' topic/desc ')]"/>
     </fo:block>
   </xsl:template>
  </xsl:stylesheet>
  

• Create an English-language variable-definition file (cfg/common/vars/en.xml) and make any necessary modifications to it. For example, the following code removes the period after the number for an ordered-list item; it also specifies that the bullet for an unordered list item should be an em dash.

  <?xml version="1.0" encoding="UTF-8"?>
  <vars xmlns="http://www.idiominc.com/opentopic/vars">
   <!-- Remove dot from list number -->
   <variable id="Ordered List Number"><param ref-name="number"/></variable>
   <!-- Change unordered list bullet to an em dash -->
   <variable id="Unordered List bullet">&#x2014;</variable>
  </vars>
  

The new plug-in directory has the following layout and files:

com.example.print-pdf/
  cfg/
    common/
      vars/
        en.xml
    fo/
      attrs/
        custom.xsl
      xsl/
        custom.xsl
    catalog.xml
  integrator.xml
  plugin.xml

Run the integration process to install the plug-in and make the print-pdf transformation available.