Sorting

The <xsl:sort> element sorts a set of nodes according to the criteria specified:

It can appear as a child of <xsl:apply-templates> or <xsl:for-each>. It can also be nested.

Sorting Example

Example 19. sort.xml

<doc>
<para>Here's a table of sales:</para>
<table>
<row><cell>3000</cell><cell>Widgets 'R' Us</cell></row>
<row><cell>2400</cell><cell>Widget Design and Implementation</cell></row>
<row><cell>10000</cell><cell>Widgets for Dummies</cell></row>
<row><cell>101</cell><cell>101 Uses for a Dead Widget</cell></row>
</table>
</doc>

Example 20. sort.xsl

<?xml version='1.0'?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                version="1.0">

<xsl:import href="element.xsl"/>

<xsl:template match="table">
  <xsl:if test="@id"><a name="{@id}"/></xsl:if>
  <table>
    <xsl:apply-templates select="row">
      <xsl:sort data-type="number" select="./cell[1]"/>
    </xsl:apply-templates>
  </table>
</xsl:template>
</xsl:stylesheet>

Example 21. sort.html

<p>Here's a table of sales:</p>
<table>
<tr>
<td>101</td><td>101 Uses for a Dead Widget</td>
</tr>
<tr>
<td>2400</td><td>Widget Design and Implementation</td>
</tr>
<tr>
<td>3000</td><td>Widgets 'R' Us</td>
</tr>
<tr>
<td>10000</td><td>Widgets for Dummies</td>
</tr>
</table>

Formatting objects and properties

XSL = XSLT + vocabulary of FOs and properties

XSL defines a powerful set of formatting objects

XSL uses (and extends) a set of Common Formatting Properties developed jointly with the CSS&FP (Cascading Style Sheet and Formatting Property) Working Group

When a result tree uses this standardized set of formatting objects and properties, then an XSL-compliant formatter can process that result tree to produce the specified output

Some XSL-FO templates

<xsl:template match="chapter">
  <fo:flow>
    <xsl:apply-templates/>
  </fo:flow>
</xsl:template>

<xsl:template match="chapter/title">
  <fo:block font-size="18pt" font-weight="bold"
            text-align="centered">
    <xsl:apply-templates/>
  </fo:block>
</xsl:template>

<xsl:template match="para">
  <fo:block font-size="12pt" space-before="1pc"
            text-align="justified">
    <xsl:apply-templates/>
  </fo:block>
</xsl:template>

<xsl:template match="emphasis">
  <fo:inline font-style="italic">
    <xsl:apply-templates/>
  </fo:inline>
</xsl:template>

Common Formatting Objects

• page-sequence--a major part (such as front or body) in which the basic page layout may differ from other parts

• flow--a chapter- or section-like division within a page-sequence

• block--a paragraph (or title or block quote, etc.)

• inline--e.g., a font change within a paragraph

• wrapper--a "transparent" object usable as either a block or inline object that has no effect other than to provide a place to hang inheritable properties

• list FOs--list-block, list-item, list-item-label, list-item-body

• graphic--references an external graphic object

• table FOs--mostly analogous to the standard (CALS, OASIS, HTML) table models