XSLT v1.0 - How to group uneven atributes?

Question

I am trying to implement a grouping using xslt on xml elements for attributes that do not really share any common value and i am not sure if i should use the muenchian grouping or not, although i already grouped my elements with this method in my code. I also searched in the forum but without luck since most groupings appear to happen on attributes with common values.

More specifically what i am trying to achieve is to print on a pdf, one line for more than one Records that have specific Ids for Att elements with value "PC" on attribute Ty (Att ty="PC"). All this should happen along with my already existing grouping.

Sample of my xml code:

<Document>
    <RecordDetails>
        <Record>
            <contact id="0001" title="Mr" forename="John" surname="Smith" ST='M'/>
            <AggSet>                
                <Att Ty="Addr" Id="43 Menelaou Street" />
                <Att Ty="PC"   Id="15230" />
                <Att Ty="Num"  Id="2580052635" />             
            </AggSet>
            <Charge Amount="3.000" PT="P" />
        </Record>
        <Record>
            <contact id="0001" title="Mr" forename="John" surname="Smith" ST='M'/>
            <AggSet>                
                <Att Ty="Addr" Id="65 Dankan Street" />
                <Att Ty="PC"   Id="15236" />
                <Att Ty="Num"  Id="2580052635" />             
            </AggSet>
            <Charge Amount="10.000" PT="P" />
        </Record>
        <Record>
            <contact id="0002" title="Dr" forename= "Amy" surname="Jones" ST='Y'/>
            <AggSet>                
                <Att Ty="Addr" Id="28 Karman Street" />
                <Att Ty="PC"   Id="15237" />
                <Att Ty="Num"  Id="2584552635" />             
            </AggSet>
            <Charge Amount="-2.000" PT="P" />
        </Record>
        <Record>    
            ...
        </Record>
    </RecordDetails>
</Document>

So for instance for records 2,3 I would like to print only 1 line due to the fact that their post codes belong to the same area for me since Ty="PC" means post and I am trying to group on a greater area basis.

I am using the follow xsl on Apache FOP:

<xsl:key name="ct" match="Record[Charge/@PT='P']" use="@ST"/>


<xsl:template match ="RecordDetails">
    <xsl:for-each select="Record[generate-id(.)=generate-id(key('ct',@ST)[1])]">
        <xsl:if test="@ST='M' and (./AggSet/Att[@Ty='PC']/@Id='15236' or ./AggSet/Att[@Ty='TZ']/@Id='15237' or ... )  ">
            <fo:table-row>                          
                    <xsl:apply-templates select="."/>                            
            </fo:table-row>
        </xsl:if> 
        <xsl:for-each select="key('ct',@ST)">                       
            <xsl:choose>                                    
                 <xsl:when test="@ST='M' and (./AggSet/Att[@Ty='PC']/@Id='15236' or ./AggSet/Att[@Ty='TZ']/@Id='15237' or ... )  "> 
                 </xsl:when>                     
                 <xsl:otherwise>
                  <fo:table-row>
                    <xsl:apply-templates select="."/>
                  </fo:table-row>
                 </xsl:otherwise>
            </xsl:choose>             
        </xsl:for-each>                             
    </xsl:for-each>
</xsl:template>

<xsl:template match="Record">
    <fo:table-cell>
        <xsl:choose>
            <xsl:when test="@ST='M' and (./AggSet/Att[@Ty='PC']/@Id='15236' or ./AggSet/Att[@Ty='TZ']/@Id='15237' or ... )">
                <fo:block text-align="center">
                    <xsl:text>Greater area</xsl:text>
                </fo:block>
            </xsl:when>
            <xsl:otherwise>
                <fo:block text-align="center">
                    <xsl:value-of select="./AggSet/Att[@Ty='PC']/@Id" />
                </fo:block>
            </xsl:otherwise>
        </xsl:choose>
    </fo:table-cell>
    <fo:table-cell>
        <xsl:choose>
            <xsl:when test="@ST='M' and (./AggSet/Att[@Ty='PC']/@Id='15236' or ./AggSet/Att[@Ty='TZ']/@Id='15237' or ... )">
                <fo:block text-align="center">
                    <xsl:value-of select="sum(//Record[@ST='M' and (./AggSet/Att[@Ty='PC']/@Id='15236' or ./AggSet/Att[@Ty='TZ']/@Id='15237' or ... )]/contact/Charge/@Amount)" />
                </fo:block>
            </xsl:when>
            <xsl:otherwise>
                <fo:block text-align="center">
                    <xsl:value-of select="./Charge/@Amount" />
                </fo:block>
            </xsl:otherwise>
        </xsl:choose>
    </fo:table-cell>
</xsl:template>

Although i have implemented this logic in the past for elements that actually share a common attribute value within my existing grouping, the above code gives me no lines at all for my wanting aggregation and i am wondering if there's something wrong with my OR conditions and for some reason it becomes false.

Am I missing something ? Any help would be much appreciated,

Thanks

Edit: As Tomalak points out in my case what I am trying to do is to implement manual groups, meaning indeed hardcoded conditions inside the code. There is no generic way to calculate these values for me now.

Answer 1

How about this approach:

<xsl:stylesheet 
  version="1.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:my="http://tempuri.org/config"
  exclude-result-prefixes="my"
>
  <my:config>
    <PC_group>
      <item>15236</item>
      <item>15237</item>
    </PC_group>
    <!-- more groups like this... -->
  </my:config>

  <!-- create a reference to our own config -->
  <xsl:variable name="config" select="document('')/*/my:config" />
  <xsl:variable name="PC_group" select="$config/PC_group" />

  <xsl:template match="RecordDetails">
    <grouped_RecordDetails>
      <xsl:apply-templates mode="group" select="Record[Charge/@PT='P']" />
    </grouped_RecordDetails>
  </xsl:template>

  <xsl:template match="Record" mode="group">
    <xsl:variable name="myPC" select="AggSet/Att[@Ty = 'PC']/@Id" />

    <!-- select all the PCs in this group -->
    <xsl:variable name="groupPCs" select="$PC_group[item = $myPC]/item" />

    <!-- identify all other members of this group -->
    <xsl:variable name="groupMembers" select=". | ../Record[
      Charge/@PT='P' and AggSet/Att[@Ty = 'PC']/@Id = $groupPCs
    ]" />

    <!-- do the actual grouping, just like the Muenchian method... -->
    <xsl:if test="generate-id() = generate-id($groupMembers[1])">

      <!--
        we are at the first Record in this group now
        all the other group members are at $groupMembers
        output whatever details you like here
      -->
      <xsl:copy-of select="." />

    </xsl:if>
  </xsl:template>

  <xsl:template match="text()[normalize-space() = '']" />

</xsl:stylesheet>

sample output

<grouped_RecordDetails>
  <Record>
    <contact id="0001" title="Mr" forename="John" surname="Smith" ST="M" />
    <AggSet>
      <Att Ty="Addr" Id="43 Menelaou Street" />
      <Att Ty="PC" Id="15230" />
      <Att Ty="Num" Id="2580052635" />
    </AggSet>
    <Charge Amount="3.000" PT="P" />
  </Record>
  <Record>
    <contact id="0001" title="Mr" forename="John" surname="Smith" ST="M" />
    <AggSet>
      <Att Ty="Addr" Id="65 Dankan Street" />
      <Att Ty="PC" Id="15236" />
      <Att Ty="Num" Id="2580052635" />
    </AggSet>
    <Charge Amount="10.000" PT="P" />
  </Record>
</grouped_RecordDetails>

---

Edit: Of course the grouping can all be done in one big, messy XPath expression, if you prefer:

<!-- identify all members of this group -->
<xsl:variable name="groupMembers" select="
  . | ../Record[
    Charge/@PT = 'P' 
    and AggSet/Att[@Ty = 'PC']/@Id = $PC_group[
          item = current()/AggSet/Att[@Ty = 'PC']/@Id
        ]/item
  ]
" />

Splitting it up into several variables makes it easier to follow, though.