N:1 mapping problem with incoming NULL value

Question

Dear experts,
i have a problem mapping an incoming Idoc to XML file. Here's the situation:
1) Structure of inbound Idoc
    ZTST00
    ZTST01 Structure: FIELDNAME, FIELDVALUE. Values: FIELDNAME = "Z1", FIELDVALUE = "4";
    ZTST01 Structure: FIELDNAME, FIELDVALUE. Values: FIELDNAME = "Z2", FIELDVALUE = null;
    ZTST01 Structure: FIELDNAME, FIELDVALUE, Values: FIELDNAME = "ZABC", FIELDVALUE = "5";
    ZTST01 Structure: FIELDNAME, FIELDVALUE. Values: FIELDNAME = "Z4", FIELDVALUE = "6";
    ZTST02
2) Resulting XML:
    LINEHEADER (1 line)
    LINEDETAIL (1 line, Structure: VALUE)
    LINEFOOTER (1 line)
3) I need to map ZTST01-FIELDVALUE to LINEDETAIL-VALUE, but only if the FIELDNAME equals "ZABC".
In my message mapping, i put an IF FIELDNAME = 'ZABC' THEN FIELDVALUE->VALUE, on context ZTST00. But because of the null value in line 2 of the Idoc, the value that is returned to the XML is "6", as the null value is disregarded and not in the queue of FIELDVALUE.
How can I put the correct value ("5") to LINEDETAIL-VALUE?
Regards
William

Answer 1

Hi William,
Simply go back to the default context ZTST01 (for both: FIELDNAME and FIELDVALUE fields) and it should be fine.
Hope this helps,
Greg