Implemented a more balanced category sort logic

* random sort order of page-entries on category pages led to unsatisfing results
* the entries are now sorted in an alternating fashion depending on their digest length
* this produces a much more consistent and balanced output

1 files changed, 40 insertions, 17 deletions

diff --git a/source/99_result/category/category.xsl b/source/99_result/category/category.xsl
index 2b54348..1713c84 100644
--- a/source/99_result/category/category.xsl
+++ b/source/99_result/category/category.xsl
@@ -2,7 +2,8 @@
 <xsl:stylesheet
 	version="1.0"
 	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
-	xmlns:math="http://exslt.org/math"
+	xmlns:xalan="http://xml.apache.org/xalan"
+	exclude-result-prefixes="xalan"
 >
 
 <xsl:include href="[utility/master.xsl]"/>
@@ -17,33 +18,55 @@
 	<xsl:value-of select="/datasource/category/entry/@handle"/>
 </xsl:template>
 
+<xsl:template name="page_entry">
+	<xsl:param name="source"/>
+
+	<li>
+		<em>»</em>
+		<a href="{$url}/page/{$source/@handle}">
+			<strong><xsl:value-of select="$source/title"/></strong>
+			<p>
+				<xsl:copy-of select="$source/digest/node()"/>
+			</p>
+		</a>
+	</li>
+</xsl:template>
+
 <xsl:template match="category/entry">
 	<h3>
 		<xsl:text>All pages categorized as &#187;</xsl:text>
 		<xsl:value-of select="@handle"/>
-		<xsl:text>&#171; in random order</xsl:text>
+		<xsl:text>&#171;</xsl:text>
 	</h3>
 	<div class="archiv columns">
 		<ul class="prettylist">
-			<xsl:for-each select="page">
-				<xsl:sort select="position() mod math:random()" order="descending"/>
+			<xsl:variable name="ceiling"  select="count(page) + 1"/>
+			<xsl:variable name="boundary" select="$ceiling div 2"/>
+
+			<xsl:variable name="sorted_pages">
+				<xsl:for-each select="page">
+					<xsl:sort select="digest/@size" order="ascending"/>
+					<xsl:copy-of select="."/>
+				</xsl:for-each>
+			</xsl:variable>
 
-				<xsl:apply-templates select="."/>
+			<xsl:for-each select="xalan:nodeset($sorted_pages)/page">
+				<xsl:variable name="index" select="position()"/>
+
+				<xsl:if test="$index &lt;= $boundary">
+					<xsl:call-template name="page_entry">
+						<xsl:with-param name="source" select="."/>
+					</xsl:call-template>
+
+					<xsl:if test="$ceiling - $index != $index">
+						<xsl:call-template name="page_entry">
+							<xsl:with-param name="source" select="xalan:nodeset($sorted_pages)/page[$ceiling - $index]"/>
+						</xsl:call-template>
+					</xsl:if>
+				</xsl:if>
 			</xsl:for-each>
 		</ul>
 	</div>
 </xsl:template>
 
-<xsl:template match="category/entry/page">
-	<li>
-		<em>»</em>
-		<a href="{$url}/page/{@handle}">
-			<strong><xsl:value-of select="title"/></strong>
-			<p>
-				<xsl:copy-of select="digest/node()"/>
-			</p>
-		</a>
-	</li>
-</xsl:template>
-
 </xsl:stylesheet>