Mapping - Referencing another segment

Question

Hello,
I have an incoming XML document that I am mapping into an IDOC.
<ASN>
...<Item>  0...999
........<ItemID>
........<PO Reference>
.............<PONum>
.............<POLine>
...<barcode>  0...999
.........<handling Unit data>
.........<delivery item>
.............<itemID>
.............<quantity>
The <item> and <barcode> segments are on the same level.  And they can each occur 0..999.  So I can have 2 item segments and 10 barcode segments for those two PO/Lines.  Or I can have 10 PO/Lines with only 3 barcodes...etc.
Using the matching <itemID> fields I'd like my mapping to fill the barcode segment of the IDOC with all the <barcode> data but also reference the matching <PONum> and <POLine> from the <item> segment. 
How can I write a "lookup" that will find the matching <itemID> so we can match the data for the IDOC segment?
Thanks,
Matt
Edited by: Matthew Herbert on Aug 4, 2011 9:49 PM

Answer 1

Thanks for the suggestions but this solution only works if the <item> and <barcode> segments are in order.  I cannot guarantee that the documents will be sent in a sorted order.
Which means I could get a document like this
<ASN>
...<Item> 0...999
........<ItemID>1
........<PO Reference>
.............<PONum>450000123
.............<POLine>1
...<Item> 0...999
........<ItemID>2
........<PO Reference>
.............<PONum>450000555
.............<POLine>1
...<Item> 0...999
........<ItemID>3
........<PO Reference>
.............<PONum>450000123
.............<POLine>2
...<barcode> 0...999
.........<handling Unit data>
.........<delivery item>
.............<itemID>1
.............<quantity>10
...<barcode> 0...999
.........<handling Unit data>
.........<delivery item>
.............<itemID>2
.............<quantity>50
.........<delivery item>
.............<itemID>3
.............<quantity>44
In the above example the EqualS/IF/Split function solution will fail. 
What I really need to is to be able to "lookup" the value in PONum when the barcode <itemID>  matches the line <itemID>.
Can this be done? 
I can write a Java UDF that will loop through everything in the <line>-<itemID> to get the correct data but if the document has 100 lines and 50 barcodes.  I will have to loop through 100 <lines> for each of the 50 barcodes. This could be a performance problem. I'm hoping there is a better solution for this.
Thanks,
Matt