[xsl] Select the nearest of two preceding siblings

["ccbranham" <ccbranham@xxxxxxxxxxx>]

Hello:

Sorry if this is too simple, but I'm still a bit new at this. I need to 
compare the relative positions of two preceding siblings and grab the value 
of the nearest one.

I'm transforming a flat document into a shallow hierachical document using 
xsl:for-each-group and group-starting-with. In the for-each-group, an 
element is created with attributes whose values are based on text from 
elements that occur before the group in document order. I've gotten this far 
(for Case 1 below), but there is variation in the input I need to account 
for (Case 2).

So these are the two cases for the input:

Case 1: With a h3
..
<p style="h1">Heading 1</p>
<p style="h2">Heading 2</p>
<p style="h3">Heading 3</p>
<p style="h4">Heading 4</p>
<p style="Standard">...</p>
<p style="Standard">...</p>
..


Case 2: No h3 and h2 has the text "Odd"
..
<p style="h1">Heading 1</p>
<p style="h2">Odd</p>
<p style="h4">Heading 4</p>
<p style="Standard">...</p>
<p style="Standard">...</p>
..


I need to create groups starting with h4, and use h1-h3 for attribute values 
or for choice in processing. So here is the desired output:

Case 1: Select the value of p[@style='h3'] for @mythiratt

..
  <myelem myfiratt="Heading 4" mysecatt="Heading 1" mythiatt="Heading
3">
     <p style="Standard">...</p>
     <p style="Standard">...</p>
     ...
  </myelem>
..


Case 2: Since the preceding p[@style='h2'] has the text "Odd" and it occurs 
ahead of the next preceding p[@style='h3'], supply a value for @mythiatt

..
  <myelem myfiratt="Heading 4" mysecatt="Heading 1" mythiatt="Oddball">
     <p style="Standard">...</p>
     <p style="Standard">...</p>
     ...
  </myelem>
..


I've set up the for-each-group, and can get the values for myfiratt and 
mysecatt easily. I'm just not sure how to do the comparison to find out 
which heading is closest in the document. Is this a simple thing to do, or 
do I need to take a different approach?

Thanks,

Craig B.