--- nfo/perl/libs/XML/XUpdate/xupdate2xsl.xml	2003/05/01 20:39:54	1.1
+++ nfo/perl/libs/XML/XUpdate/xupdate2xsl.xml	2003/05/07 13:01:33	1.6
@@ -2,14 +2,28 @@
   
   <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   
-      <!--
-      Purpose of this XML Stylesheet is to implement a set of templates 
-      to translate XUpdate lingo into an intermediate xslt stylesheet 
-      which actually performs the update to the original xml document
-      in a second step.
-      The required glue code - written in Perl - is available in module 
-      XML::XUpdate::XSLT. Please have a look at this to port it to other
-      languages.
+      <!--
+      
+        xupdate2xsl: Translate XML document from namespace 'xupdate' to 'xsl'.
+        
+        Purpose of this XML Stylesheet is to implement a set of templates 
+        to translate XUpdate lingo into an intermediate xslt stylesheet 
+        which actually performs the update to the original xml document
+        in a second step.
+        
+        The required glue code - written in Perl - is available in module 
+        XML::XUpdate::XSLT. Please have a look at this in order to write
+        code to use this stylesheet from other language bindings.
+
+        Please have a look at the XUpdate specs and associated resources:
+          Requirements: http://www.xmldb.org/xupdate/xupdate-req.html
+          Working Draft: http://www.xmldb.org/xupdate/xupdate-wd.html
+
+        ChangeLog:
+          2003-04-30: first alpha
+          2003-05-01: works: xupdate:insert-after (elements/attributes)
+          2003-05-06: works: xupdate:insert-before (elements/attributes)
+
       -->
       
       <xsl:output method="xml" />
@@ -21,25 +35,43 @@
       <!-- override some builtin rules: see http://www.w3.org/TR/xslt#built-in-rule -->
       <xsl:template match="comment()"><xsl:call-template name="passthru" /></xsl:template>
   
+      
       <!-- 2. This is the translation part: XUpdate becomes XSLT -->
       
-      <!-- This node "encapsulates" common infrastructure. -->
+      <!-- lib -->
+      <!-- This node "encapsulates" common core infrastructure. -->
       <xsl:template match="xupdate:modifications">
   
-          <!-- 1. This is the passthru logic (copy all untouched nodes). -->
-          <!-- in fact this is the xsl from above translated to be able to be generated by xsl itself! -->
-              <xsl:comment> 1. passthru logic </xsl:comment>
-              <xsl:element name="xsl:template">
-                  <xsl:attribute name="name">passthru</xsl:attribute>
-                  <xsl:element name="xsl:copy"><xsl:element name="xsl:apply-templates" /></xsl:element>
-              </xsl:element>
-              <xsl:element name="xsl:template">
-                  <xsl:attribute name="match">*</xsl:attribute>
-                  <xsl:element name="xsl:call-template"><xsl:attribute name="name">passthru</xsl:attribute></xsl:element>
+        <!-- <xsl:template name="identity_template_rule"> -->
+        <xsl:element name="xsl:template">
+          <xsl:attribute name="name">identity_template_rule</xsl:attribute>
+
+              <!-- An "identity template rule" - original version by Mike Kay, Software AG -->
+              <!-- Please visit [http://p2p.wrox.com/archive/xslt/2001-06/98.asp] -->
+              <!-- Translated to "self hosting xsl": Andreas Motl, andreas.motl@ilo.de -->
+              <!-- FIXME: Could this be used to replace passthru-logic at 1. ? -->
+              <xsl:element name="xsl:copy">
+                <xsl:element name="xsl:copy-of">
+                  <xsl:attribute name="select">@*</xsl:attribute>
+                </xsl:element>
+                <xsl:element name="xsl:apply-templates" />
               </xsl:element>
-              <xsl:element name="xsl:template">
-                  <xsl:attribute name="match">comment()</xsl:attribute>
-                  <xsl:element name="xsl:call-template"><xsl:attribute name="name">passthru</xsl:attribute></xsl:element>
+
+        </xsl:element>
+        <!-- </xsl:template> -->
+
+              <!-- 
+                  1. Note: Former custom passthru logic (copy all untouched nodes)
+                      now completely replaced by Mike Kay's "identity template rule". 
+                  What is left here is just the required overriding of some builtin rules
+                  to (e.g.) not to loose comments.
+              -->
+              <xsl:comment> 1. override built-in rules </xsl:comment>
+              <!-- override some builtin rules: see http://www.w3.org/TR/xslt#built-in-rule -->
+              <xsl:element name="xsl:template"><xsl:attribute name="match">comment()</xsl:attribute>
+                  <xsl:element name="xsl:call-template">
+                    <xsl:attribute name="name">identity_template_rule</xsl:attribute>
+                  </xsl:element>
               </xsl:element>
   
           <!-- continue with all inline nodes -->
@@ -47,28 +79,348 @@
   
       </xsl:template>
   
+
+
+
+
+      <!-- code -->
       <!-- This node "encapsulates" infrastructure for handling the directives. -->
+
+      <!-- Dispatch all "XUpdate Services" here. -->
+      <!-- FIXME: Actually implement action = "CREATE|RETRIEVE|UPDATE|DELETE"!!! -->
+
+      <!-- 
+        xsl for XUpdate Services [2 XUpdate Syntax] [2.3 Modifications]
+      -->
+
+      <!-- xsl for [2.4 Inserts] -->
       <xsl:template match="xupdate:insert-after">
-          <xsl:comment> 2. context finder </xsl:comment>
-          <xsl:apply-templates />
+          <!-- <xsl:variable name="select" select="@select">Hello World!</xsl:variable> -->
+          <xsl:call-template name="findcontext">
+            <xsl:with-param name="service">Insert</xsl:with-param>
+            <xsl:with-param name="position">after</xsl:with-param>
+          </xsl:call-template>
+      </xsl:template>
+
+      <!-- xsl for [2.4 Inserts] -->
+      <xsl:template match="xupdate:insert-before">
+          <xsl:call-template name="findcontext">
+            <xsl:with-param name="service">Insert</xsl:with-param>
+            <xsl:with-param name="position">before</xsl:with-param>
+          </xsl:call-template>
+      </xsl:template>
+
+      <!-- xsl for [2.5 Append] -->
+      <xsl:template match="xupdate:append">
+          <xsl:call-template name="findcontext">
+            <xsl:with-param name="service">Append</xsl:with-param>
+            <!-- <xsl:with-param name="position">inline</xsl:with-param> -->
+            <xsl:with-param name="test">.</xsl:with-param>
+          </xsl:call-template>
+      </xsl:template>
+
+      <!-- xsl for [2.6 Update] -->
+      <xsl:template match="xupdate:update">
+          <xsl:call-template name="findcontext">
+            <xsl:with-param name="service">Update</xsl:with-param>
+            <!-- <xsl:with-param name="position">after</xsl:with-param> -->
+            <xsl:with-param name="test">.</xsl:with-param>
+          </xsl:call-template>
+      </xsl:template>
+
+      <!-- xsl for [2.7 Remove] -->
+      <xsl:template match="xupdate:remove">
+          <xsl:call-template name="findcontext">
+            <xsl:with-param name="service">Remove</xsl:with-param>
+            <!-- <xsl:with-param name="position">after</xsl:with-param> -->
+            <xsl:with-param name="test">.</xsl:with-param>
+          </xsl:call-template>
+      </xsl:template>
+
+      <!-- xsl for [2.8 Rename] -->
+      <xsl:template match="xupdate:rename">
+          <xsl:call-template name="findcontext">
+            <xsl:with-param name="service">Rename</xsl:with-param>
+            <!-- <xsl:with-param name="position">after</xsl:with-param> -->
+            <xsl:with-param name="test">.</xsl:with-param>
+          </xsl:call-template>
+      </xsl:template>
+
+
+
+      <xsl:template name="findcontext">
+
+        <xsl:comment> 2. context finder </xsl:comment>
+
+        <!-- new of 2003-05-06: introducing parameters here to handle all cases -->
+        <xsl:param name="service" />
+        <xsl:param name="position" />
+        <!-- new of 2003-05-07: replacement for test if undef -->
+        <xsl:param name="test" />
+        
+        <!--
+        <xsl:comment>
+          service: <xsl:value-of select="$service" />
+          position: <xsl:value-of select="$position" />
+          test: <xsl:value-of select="$test" />
+        </xsl:comment>
+        -->
+
+          <!-- this resembles some parts of the CRUD API - retranslated to self-hosting xsl -->
+
+          <!-- V1 -->
+          <!-- <xsl:element name="xsl:template"> -->
+              <!-- <xsl:attribute name="match"><xsl:value-of select="@select" /></xsl:attribute> -->
+          
+          <!-- fallback -->
+          <xsl:element name="xsl:template">
+              <xsl:attribute name="match">*</xsl:attribute>
+              <xsl:element name="xsl:call-template">
+                <xsl:attribute name="name">identity_template_rule</xsl:attribute>
+                <!-- <xsl:attribute name="name">passthru</xsl:attribute> -->
+              </xsl:element>
+          </xsl:element>
+
+          <!-- V2 -->
+          <xsl:element name="xsl:template">
+              <!-- <xsl:attribute name="match">/addresses/address</xsl:attribute> -->
+              <!-- <xsl:attribute name="match">*</xsl:attribute> -->
+              <xsl:attribute name="match"><xsl:value-of select="@select" /></xsl:attribute>
+
+          <xsl:element name="xsl:choose">
+              <!-- <xsl:attribute name="match"><xsl:value-of select="@select" /></xsl:attribute> -->
+            <xsl:element name="xsl:when">
+              <!-- <xsl:attribute name="test"><xsl:value-of select="@select" /></xsl:attribute> -->
+              <xsl:attribute name="test"><xsl:value-of select="@test" /><xsl:value-of select="$test" /></xsl:attribute>
+
+              <xsl:choose>
+                <xsl:when test="{$service}=Insert">
+
+                <xsl:comment> 2.a. Insert </xsl:comment>
+
+                <!-- Implementation of "xupdate:insert-before" -->
+                <xsl:choose>
+                  <xsl:when test="{$position}=before">
+                    <xsl:apply-templates />
+                  </xsl:when>
+                </xsl:choose>
+  
+                <!-- call the "identity template rule" to passthru all childnodes -->
+                <xsl:element name="xsl:call-template">
+                  <xsl:attribute name="name">identity_template_rule</xsl:attribute>
+                  <!-- <xsl:attribute name="name">passthru</xsl:attribute> -->
+                </xsl:element>
+  
+                <!-- Implementation of "xupdate:insert-after" -->
+                <xsl:choose>
+                  <xsl:when test="{$position}=after">
+                    <xsl:apply-templates />
+                  </xsl:when>
+                </xsl:choose>
+
+                </xsl:when>
+                
+                <!-- Implementation of "xupdate:append" -->
+                <xsl:when test="{$service}=Append">
+                <xsl:comment> 2.b. Append </xsl:comment>
+                  <!-- V1 -->
+                  <!-- <xsl:apply-templates /> -->
+                  <!-- V2 -->
+                  <xsl:element name="xsl:copy">
+                    <!--
+                    <xsl:element name="xsl:copy-of">
+                      <xsl:attribute name="select">@*</xsl:attribute>
+                    </xsl:element>
+                    -->
+                    <!-- Keep content ... -->
+                    <xsl:element name="xsl:apply-templates" />
+                    <!-- Append this: -->
+                    <xsl:apply-templates />
+                  </xsl:element>
+                </xsl:when>
+                
+                <!-- Implementation of "xupdate:update" -->
+                <xsl:when test="{$service}=Update">
+                <xsl:comment> 2.c. Update </xsl:comment>
+                  <!-- V1 -->
+                  <!-- <xsl:apply-templates /> -->
+                  <!-- V2 -->
+                  <xsl:element name="xsl:copy">
+                    <!--
+                    <xsl:element name="xsl:copy-of">
+                      <xsl:attribute name="select">@*</xsl:attribute>
+                    </xsl:element>
+                    -->
+                    <!-- Keep content ... -->
+                    <!-- <xsl:element name="xsl:apply-templates" /> -->
+                    <!-- Add (replace through) this: -->
+                    <xsl:apply-templates />
+                  </xsl:element>
+                </xsl:when>
+
+                <!-- Implementation of "xupdate:remove" -->
+                <xsl:when test="{$service}=Remove">
+                  <xsl:comment> 2.d. Remove </xsl:comment>
+                </xsl:when>
+
+                <!-- Implementation of "xupdate:rename" -->
+                <xsl:when test="{$service}=Rename">
+                  <xsl:comment> 2.e. Rename (Remove context and Append modified identity template) </xsl:comment>
+                  
+                  <xsl:comment> [5.a.] modify node name </xsl:comment>
+                  <xsl:element name="xsl:element">
+                    <!-- this renames the node (change the "name"-attribute) -->
+                    <xsl:attribute name="name">
+                      <xsl:apply-templates />
+                    </xsl:attribute>
+                    <!-- this propagates the original content -->
+                    <xsl:element name="xsl:apply-templates" />
+                  </xsl:element>
+
+                </xsl:when>
+
+              </xsl:choose>
+
+            </xsl:element>
+            <xsl:element name="xsl:otherwise">
+
+              <!-- call the "identity template rule" to passthru all childnodes -->
+              <xsl:element name="xsl:call-template">
+                <xsl:attribute name="name">identity_template_rule</xsl:attribute>
+                <!-- <xsl:attribute name="name">passthru</xsl:attribute> -->
+              </xsl:element>
+
+              <!-- <xsl:apply-templates /> -->
+            </xsl:element>
+
+          </xsl:element>
+          </xsl:element>
+
+          <!-- <xsl:apply-templates /> -->
+          
       </xsl:template>
   
-      <!-- This node passes through all attributes and childnodes rewriting the tagname only. -->
+  
+      <!-- 
+        Rewrite XUpdate elements to XSLT elements.
+        These templates pass through all attributes 
+        and childnodes rewriting the tagname only. 
+        FIXME: The redundant encoding for each XUpdate
+        element type seems dummy. Could this be stripped
+        shorter somehow sometimes?
+      -->
+
+      <!-- 
+        xsl for [2.4 Inserts]
+      -->
+
+      <!-- xsl for [2.4.1 Creating Elements] -->
       <xsl:template match="xupdate:element">
-          <xsl:comment> 3. rewrite / vivify elements/attributes </xsl:comment>
+          <xsl:comment> 3.a. vivify generic node </xsl:comment>
           <xsl:element name="xsl:element">
               <xsl:copy-of select="@*"/>
               <xsl:apply-templates />
           </xsl:element>
       </xsl:template>
   
-      <!-- This node passes through all attributes and childnodes rewriting the tagname only. -->
+      <!-- xsl for [2.4.2 Creating Attributes] -->
       <xsl:template match="xupdate:attribute">
+          <xsl:comment> 3.b. vivify node attributes </xsl:comment>
           <xsl:element name="xsl:attribute">
               <xsl:copy-of select="@*"/>
               <xsl:apply-templates />
           </xsl:element>
       </xsl:template>
   
-  </xsl:stylesheet>
+      <!-- xsl for [2.4.3 Creating Text] -->
+      <xsl:template match="xupdate:text">
+          <xsl:comment> 4.a. vivify text node </xsl:comment>
+          <xsl:element name="xsl:text">
+              <xsl:copy-of select="@*"/>
+              <xsl:apply-templates />
+          </xsl:element>
+      </xsl:template>
+
+      <!-- xsl for [2.4.4 Creating Processing Instructions] -->
+      <xsl:template match="xupdate:processing-instruction">
+          <xsl:comment> 4.b. vivify PI node </xsl:comment>
+          <xsl:element name="xsl:processing-instruction">
+              <xsl:copy-of select="@*"/>
+              <xsl:apply-templates />
+          </xsl:element>
+      </xsl:template>
+
+      <!-- xsl for [2.4.5 Creating Comments] -->
+      <xsl:template match="xupdate:comment">
+          <xsl:comment> 4.c. vivify comment node </xsl:comment>
+          <xsl:element name="xsl:comment">
+              <xsl:copy-of select="@*"/>
+              <xsl:apply-templates />
+          </xsl:element>
+      </xsl:template>
+
+
+      <!-- 
+        xsl for [2.9 Variables and Values of Variables]
+        Encapsulates block payload into a named template.
+      -->
+      <xsl:template match="xupdate:variable">
+          <xsl:comment> 5.a. vivify xsl-element "variable" </xsl:comment>
+          
+          <xsl:element name="xsl:template">
+              <xsl:attribute name="name">Variables</xsl:attribute>
+          
+              <!--
+              <xsl:element name="xsl:variable">
+                  <xsl:attribute name="name"><xsl:value-of select="@name" /></xsl:attribute>
+              -->
+              
+              <xsl:choose>
+              
+                <!-- Mode 1 [spec]: just evaluate as (sub-)selection if "select"-attribute is not empty -->
+                <xsl:when test="@select!=">
+                  <xsl:element name="xsl:apply-templates">
+                      <xsl:attribute name="select"><xsl:value-of select="@select" /></xsl:attribute>
+                  </xsl:element>
+                </xsl:when>
+                
+                <!-- Mode 2 [feature]: in other cases: pass thru the current node w/o any operation(s) on it -->
+                <xsl:otherwise>
+                    <xsl:value-of select="." />
+                </xsl:otherwise>
+                    
+              </xsl:choose>
+
+              <!--
+              </xsl:element>
+              -->
+
+          </xsl:element>
+
+      </xsl:template>
+
+      <!-- 
+        xsl for [2.9 Variables and Values of Variables]
+        Calls encapsulated named template "Variables" 
+        for each occourance of an "xupdate:value-of" element.
+      -->
+      <xsl:template match="xupdate:value-of">
+          <xsl:comment> 5.b. vivify xsl-element "value-of" </xsl:comment>
+          <xsl:element name="xsl:call-template">
+            <xsl:attribute name="name">Variables</xsl:attribute>
+          </xsl:element>
+          
+        <!-- is this required any more??? -->
+        <xsl:element name="xsl:value-of">
+              <xsl:copy-of select="@*"/>
+              <!-- <xsl:apply-templates /> -->
+              <!-- this propagates the original content -->
+              <!-- <xsl:element name="xsl:apply-templates"> -->
+                <!-- <xsl:attribute name="" > -->
+              <!-- </xsl:element> -->
+          </xsl:element>
+      </xsl:template>
+
+
+</xsl:stylesheet>
   
\ No newline at end of file