[xslt] Flattenning XML

["Sabu Francis (Personal)" <sf sabufrancis com>]

Hi:
I would appreciate if I can get some help on an XSLT transformation.

I need to flatten an XML tree which can be of any structure with any 
number of elements. (The element names in the original XML are not 
known) The clue to flattening it is an attribute, say 'flatten' and on 
its presence in the element (flatten="yes") the XSLT transformation 
should isolate that tree fragment and take it out of the parent tree and 
flatten it further. Individual pieces of the element data are collected 
into our own element called a "snip"

<aa flatten="yes">
    This is a test
        <bb flatten="yes">
             of things
          </bb>
    that can can be done in XSLT
</aa>

should flatten to

<topic elemname="aa" id="pqrs" parentID="nil" >
  <snip id="xyz" parentID="pqrs" >This is a test</snip>
   <snip id="123" parentID="pqrs">that can be done in XSLT</snip>
</topic>
<topic elemname="bb" id="zzz" parentID="xyz">
     <snip id="hhh" parentID="zzz">of things</snip>
</topic>

As you can see, though the structure has been flattened out, I can still 
recreate the old XML file because the nested structure  has been passed 
along via the attributes "id" and "parentID". The name of the original 
element is also passed along. They can be used to walk up the nested 
structure back again.

Now I've been able to achieve this partially  (i.e. it works on certain 
kinds of XML files) but I need this to work in ALL situations.

The key portion of the XSLT I used was this:

<xsl:template name="deepCpy">
   <xsl:for-each select="descendant-or-self::*/text()">
   <xsl:choose>
   <xsl:when test="not(../@flatten )">
   <xsl:call-template name="applysnip" /> <!--the template that does 
the creating of the snip elements -->
   </xsl:when>
    </xsl:choose>
 </xsl:for-each>
</xsl:template>

In the above, it is obvious that the test will pass only when the 
attribute 'flatten' is not present. But then such a test will detect 
ONLY those elements where the "flatten" attribute is given. It will not 
detect those elements that are not direct children of elements which 
have the "flatten" attribute

What else can be done?

Regards
Sabu