Group By XSLT 1.0, group of groups

Question

I kind of need to create "group of groups" using XSLT.

Below are my XML and XSL files. I used this SO link to apply Muenchian grouping. I have tried to shorten the file and show only the required elements that represents the problem.

XML FILE

<IO_SearchShoppingFilesResult xmlns="http://schemas.datacontract.org/2004/07/Trevoo.WS.IO.Shopping" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<ShoppingFiles
 xmlns:a="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Shopping"
 xmlns:b="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Air">
    <a:T_ShoppingFile>
        ....
        <b:T_AirBookingItem>
            ...
            <a:LocalPaxType>ADT</a:LocalPaxType>
            ...
        </b:T_AirBookingItem>
        <b:T_AirBookingItem>
            ...
            <a:LocalPaxType>CHD</a:LocalPaxType>
            ...
        </b:T_AirBookingItem>
        <b:T_AirBookingItem>
            ...
            <a:LocalPaxType>INF</a:LocalPaxType>
            ...
        </b:T_AirBookingItem>
        ...
    </a:T_ShoppingFile>

    <a:T_ShoppingFile>
        ....
        <b:T_AirBookingItem>
            ...
            <a:LocalPaxType>ADT</a:LocalPaxType>
            ...
        </b:T_AirBookingItem>
        ...
    </a:T_ShoppingFile>
</ShoppingFiles>
</IO_SearchShoppingFilesResult>

XSL FILE

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:res="http://schemas.datacontract.org/2004/07/Trevoo.WS.IO.Shopping"
xmlns:a="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Shopping"
xmlns:b="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Air"
xmlns:c="http://schemas.microsoft.com/2003/10/Serialization/Arrays"
xmlns:bb="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Shopping.Views">
<xsl:output method="xml" indent="yes" />


<xsl:key name="travelerGroup"
    match="res:IO_SearchShoppingFilesResult/res:ShoppingFiles/a:T_ShoppingFile[position()=1]/a:AirBookings/b:T_AirBooking/b:BookingItems/b:T_AirBookingItem"
    use="b:PaxReference/a:LocalPaxType" />

<xsl:template match="/">
    <xsl:element name="PNRViewRS">
        <xsl:apply-templates
            select="res:IO_SearchShoppingFilesResult/res:ShoppingFiles" />
    </xsl:element>      
</xsl:template>

<xsl:template match="res:ShoppingFiles">
    <!-- For FareGroup, Traveler, Telephone, EmailAddress -->
    <xsl:apply-templates select="a:T_ShoppingFile" />
    ...
</xsl:template>

<xsl:template match="a:T_ShoppingFile">
    ...
    <xsl:apply-templates
            select="a:AirBookings/b:T_AirBooking/b:BookingItems/b:T_AirBookingItem[generate-id() = generate-id(key('travelerGroup', b:PaxReference/a:LocalPaxType)[1])]" />
    ...
</xsl:template>
...
<xsl:template match="b:T_AirBookingItem">
    ...
                    <!-- Line 1 -->
        <xsl:value-of
            select="count(key('travelerGroup', b:PaxReference/a:LocalPaxType))" />  
    ...

</xsl:template>

As one can see, I have applied key on <b:T_AirBookingItem>. And multiple <b:T_AirBookingItem> are present in multiple <a:T_ShoppingFile>.

Now, I want to handle each <a:T_ShoppingFile> separately and then apply grouping on all the <b:T_AirBookingItem> present in it. What happens here in this code is that all the <b:T_AirBookingItem> of all the <a:T_ShoppingFile> are grouped all together at a time.

Line 1 shows one of the result of this transformation. It should show total number of <b:T_AirBookingItem> of a particular <a:LocalPaxType> (say ADT) for a single <a:T_ShoppingFile>. However, it considers all the <b:T_AirBookingItem> in the whole of XML instead.

So where I should get "1" number of ADTs, I am getting "2".

How do I deal with it?

Answer 1

It sound like you want to make use of a compound key, consisting of more than one element. In this case you are gouping by a:T_ShoppingFile and a:LocalPaxType, so you probably need something like this

<xsl:key 
   name="item" 
   match="b:T_AirBookingItem" 
   use="concat(generate-id(..) , '|', a:LocalPaxType)" />

Then, for each a:T_ShoppingFile to get the unique a:LocalPaxType records, you just do this

<xsl:apply-templates 
  select="b:T_AirBookingItem[generate-id() 
    = generate-id(key('item', concat(generate-id(..) , '|', a:LocalPaxType))[1])]" />

Here is the full XSLT

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:res="http://schemas.datacontract.org/2004/07/Trevoo.WS.IO.Shopping" xmlns:a="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Shopping" xmlns:b="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Air" xmlns:c="http://schemas.microsoft.com/2003/10/Serialization/Arrays" xmlns:bb="http://schemas.datacontract.org/2004/07/Trevoo.WS.Entities.Shopping.Views" exclude-result-prefixes="res a b c bb">
   <xsl:output method="xml" indent="yes"/>

   <xsl:key name="item" match="b:T_AirBookingItem" use="concat(generate-id(..) , '|', a:LocalPaxType)"/>

   <xsl:template match="/">
      <xsl:apply-templates select="//a:T_ShoppingFile"/>
   </xsl:template>

   <xsl:template match="a:T_ShoppingFile">
      <file number="{position()}">
         <xsl:apply-templates select="b:T_AirBookingItem[generate-id() = generate-id(key('item', concat(generate-id(..) , '|', a:LocalPaxType))[1])]"/>
      </file>
   </xsl:template>

   <xsl:template match="b:T_AirBookingItem">
      <result>
         <xsl:value-of select="concat(a:LocalPaxType, ' * ', count(key('item', concat(generate-id(..) , '|', a:LocalPaxType))), '&#13;')"/>
      </result>
   </xsl:template>
</xsl:stylesheet>

When applied to your XML, the following is output

<file number="1">
   <result>ADT * 1</result>
   <result>CHD * 1</result>
   <result>INF * 1</result>
</file>
<file number="2">
   <result>ADT * 1</result>
</file>

Obviously, this shows results for all a:T_ShoppingFile and a:LocalPaxType. If you wanted to restrict to a particular a:LocalPaxType you could do something like this (although you would probably want to parameterise the value, rather than hard-code ADT

   <xsl:template match="a:T_ShoppingFile">
      <file number="{position()}">
         <xsl:value-of select="count(key('item', concat(generate-id() , '|', 'ADT')))" />
      </file>
   </xsl:template>