fix the <meta name="keywords"/> tag process according to Opale's schema

hdoc_to_opale/xsl/transformation2.xsl

@@ -5,6 +5,7 @@
   xmlns:sc="http://www.utc.fr/ics/scenari/v3/core"
   xmlns:op="utc.fr:ics/opale3"
   xmlns:sp="http://www.utc.fr/ics/scenari/v3/primitive"
+  xmlns:fn="http://www.w3.org/2005/xpath-functions"
   >
   <xsl:output method="xml" indent="yes" encoding="UTF-8"/>
   
@@ -25,7 +26,12 @@
         </sp:title>
         <sp:info>
           <op:info>
-            <xsl:apply-templates select="./h:meta"/>
+            <sp:keywds>
+              <op:keywds>
+                <xsl:apply-templates select="//h:meta[@name='keywords']"/> <!-- Keywords tag is processed separatly -->
+              </op:keywds>
+            </sp:keywds>
+            <xsl:apply-templates select="./h:meta[@name != 'keywords']"/>
 
             <!-- Author: in case several authors are specified, we don't want to get an error for not respecting the schema -->
             <xsl:if test="./h:meta[@name='author']">
@@ -58,17 +64,27 @@
             </xsl:if>
         </xsl:for-each>
     </xsl:template>
+  
+  <!-- 
+    The keywords tag is processed separatly 
+    because according to the Hdoc Rng schema
+    there might be multiple <meta name="keywords" tags
+    
+    This allow us to treat all the different tags 
+    and merge them according to Opale schema
+  -->
+  <xsl:template match="h:meta[@name='keywords']" priority="1">
+      <xsl:for-each select="fn:tokenize(./@content,',')">
+        <sp:keywd>
+          <xsl:value-of select="normalize-space(.)"/>
+        </sp:keywd>
+      </xsl:for-each>
+    </xsl:template>
 
     <xsl:template match="h:meta[@name]">
     <xsl:choose>
       <xsl:when test="./@name = 'description'"/> <!-- Unsupported : Opale doesn't provide any description metadata. -->
-      <xsl:when test="./@name = 'keywords'"> <!-- This is the least to do, since there's no specific format for keywords in hdoc. -->
-        <sp:keywds>
-          <op:keywds>
-            <sp:keywd><xsl:value-of select="./@content"/></sp:keywd>
-          </op:keywds>
-        </sp:keywds>
-      </xsl:when>
+      <xsl:when test="./@name = 'keywords'"/> <!-- Done above -->
       <xsl:when test="./@name = 'author'"/> <!-- Done above -->
       <xsl:when test="./@name = 'rights'">
         <xsl:choose>