Handle exercise groups better in LaTeX output

PreTeXtBook · Mar 4, 2015 · 4671ed9 · 4671ed9
1 parent d840d49
commit 4671ed9
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Showing 2 changed files with 42 additions and 14 deletions.
diff --git a/examples/sample-article.xml b/examples/sample-article.xml
@@ -1280,6 +1280,30 @@ the xsltproc executable.
                 </exercise>
 
             </exercises>
+
+            <p>Another subsection of exercises, which begins and ends with an exercise group, and has two consecutive exercise groups.</p>
+
+            <exercises>
+                <title>More Exercises</title>
+                <exercisegroup>
+                    <introduction><p>Introduction to first exercise group.</p></introduction>
+                    <exercise>
+                        <statement><p>Only exercise of first group.</p></statement>
+                    </exercise>
+                    <conclusion><p>Conclusion to first exercise group.</p></conclusion>
+                </exercisegroup>
+                <exercisegroup>
+                    <introduction><p>Introduction to second exercise group.</p></introduction>
+                    <exercise>
+                        <statement><p>First exercise of second group.</p></statement>
+                    </exercise>
+                    <exercise>
+                        <statement><p>Second exercise of second group.</p></statement>
+                    </exercise>
+                    <conclusion><p>Conclusion to second exercise group.</p></conclusion>
+                </exercisegroup>
+            </exercises>
+
         </section>
 
         <section>

diff --git a/xsl/mathbook-latex.xsl b/xsl/mathbook-latex.xsl
@@ -1057,27 +1057,19 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
         <xsl:apply-templates select="author" mode="name-list"/>
         <xsl:text>}}\par\bigskip&#xa;</xsl:text>
     </xsl:if>
-    <!-- Exceptional handling for exercises, references needs to be abstracted away -->
+    <!-- Exceptional handling for references needs to be abstracted away -->
     <xsl:apply-templates select="introduction" />
     <!-- Exercises, references are in managed description lists -->
     <xsl:if test="local-name(.)='references'">
         <xsl:text>%% If this is a top-level references&#xa;</xsl:text>
         <xsl:text>%%   you can replace with "thebibliography" environment&#xa;</xsl:text>
     </xsl:if>
-    <!-- Could be no contents (just an introduction), then -->
-    <!-- LaTeX chokes on empty list, so check for entries  -->
-    <xsl:if test="local-name(.)='exercises' and .//exercise">
-        <xsl:text>\begin{exerciselist}&#xa;</xsl:text>
-    </xsl:if>
     <xsl:if test="local-name(.)='references' and .//biblio">
         <xsl:text>\begin{referencelist}&#xa;</xsl:text>
     </xsl:if>
     <!-- Process the remaining contents -->
     <xsl:apply-templates select="*[not(self::title or self::author or self::introduction or self::conclusion)]"/>
     <!-- Exercises, references are in managed description lists -->
-    <xsl:if test="local-name(.)='exercises' and .//exercise">
-        <xsl:text>\end{exerciselist}&#xa;</xsl:text>
-    </xsl:if>
     <xsl:if test="local-name(.)='references' and .//biblio">
         <xsl:text>\end{referencelist}&#xa;</xsl:text>
     </xsl:if>
@@ -1139,20 +1131,28 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
 <!-- typically instructions for a list of similar exercises -->
 <!-- Commentary goes in an introduction and/or conclusion   -->
 <xsl:template match="exercisegroup">
-    <xsl:text>\end{exerciselist}&#xa;</xsl:text>
     <xsl:apply-templates select="introduction" />
-    <xsl:text>\setlength{\parskip}{0pt}</xsl:text>
-    <xsl:text>\begin{exerciselist}[leftmargin=2em,labelindent=2em]&#xa;</xsl:text>
     <xsl:apply-templates select="exercise"/>
-    <xsl:text>\end{exerciselist}&#xa;</xsl:text>
     <xsl:apply-templates select="conclusion" />
-    <xsl:text>\begin{exerciselist}&#xa;</xsl:text>
+    <xsl:text>\par\smallskip\noindent&#xa;</xsl:text>
 </xsl:template>
 
 <!-- An exercise in an "exercises" subdivision             -->
 <!-- is a list item in a description list                  -->
 <!-- TODO: parameterize as a backmatter item, new switches -->
+<!-- TODO: would an "exercisegrouplist" allow parameters to move to preamble? -->
 <xsl:template match="exercises/exercise|exercisegroup/exercise">
+    <!-- Start a list right before first exercise of subdivision, or of a group -->
+    <xsl:choose>
+        <xsl:when test="not(preceding-sibling::exercise) and parent::exercises">
+            <xsl:text>\begin{exerciselist}&#xa;</xsl:text>
+        </xsl:when>
+        <!-- Tweak parameters inside a group for indent -->
+        <xsl:when test="not(preceding-sibling::exercise) and parent::exercisegroup">
+            <xsl:text>\setlength{\parskip}{0pt}&#xa;</xsl:text>
+            <xsl:text>\begin{exerciselist}[leftmargin=2em,labelindent=2em]&#xa;</xsl:text>
+        </xsl:when>
+    </xsl:choose>
     <xsl:text>\item[</xsl:text>
     <xsl:apply-templates select="." mode="origin-id" />
     <xsl:text>.]</xsl:text>
@@ -1176,6 +1176,10 @@ along with MathBook XML.  If not, see <http://www.gnu.org/licenses/>.
     <xsl:if test="solution and $exercise.text.solution='yes'">
         <xsl:apply-templates select="solution" />
     </xsl:if>
+    <!-- close list if no more exercise in subdivision or in group -->
+    <xsl:if test="not(following-sibling::exercise)">
+        <xsl:text>\end{exerciselist}&#xa;</xsl:text>
+    </xsl:if>
 </xsl:template>
 
 <!-- An exercise statement is just a container -->