Message Mapping - Node's sub-levels navigation

Question

Hi all,
How should I code in order to navigate between different levels of a given node of the source structure?
example:
Main
  Struct_11
    Struct1101
      Field_1101_A
      Field_1101_B
    Struct1102
      Field_1102_A
      Field_1102_B
  Struct_22
    Struct2201
      Field_2201_A
      Field_2201_B
    Struct2202
      Field_2202_A
      Field_2202_B
In the sample above, how should I do to map the node Struct_11 and, within a UDF (or some other way, but I only imagine through a Java UDF), access and validate Struct1101-Field_1101_A, or Struct1102-Field_1102_B, etc?
If someone could provide me with a sample code, it'd help me.
Thank you!

Answer 1

Mark, tks. It helped.
I could do all that I needed withing the XML working as a text.
The only problem now is that, the target structure must be built according to the source cardinality (N..N).
In the sample bellow, see that in the source structure, the Struct_11 repeat 3 times. In the 1st and 3rd, it contains the substructure Struct1101. I have to check if Struct1101 exists, if so, I have to take the Field_1101_A and validate if it's equal to WE. If yes, then the correspondent Field_1101_B has to be sent to target <row> field.
In the 2nd occurrence, there NO Struct1101, so the UDF returns #void#.
UDF to map Struct_11:
int v_pos1, v_pos2, v_start = 0;
String v_Struct1101 = "Struct1101";
String v_WE = "WE";
String v_FieldA = "<Field_1101_A>WE</Field_1101_A>";
String v_FieldB = "";
v_pos1 = Item.indexOf(v_Struct1101);
if(v_pos1 >= 0){
     v_pos2 = Item.indexOf(v_FieldA);
     v_start = v_pos2 + 32;
     v_FieldB = Item.substring(v_start, v_start+10);
}else{
          v_FieldB = "#void#";
return v_FieldB;
Source
<Main>
  <Struct_11>
    <Struct1101>
      <Field_1101_A>WE</Field_1101_A>
      <Field_1101_B>110</Field_1101_B>
    </Struct1101>
    <Struct1102>
      <Field_1102_A>ZS</Field_1102_A>
      <Field_1102_B>222</Field_1102_B>
    </Struct1102>
  </Struct_11>
  <Struct_11>
    <Struct1102>
      <Field_1102_A>ZS</Field_1102_A>
      <Field_1102_B>222</Field_1102_B>
    </Struct1102>
  </Struct_11>
  <Struct_11>
    <Struct1101>
      <Field_1101_A>WE</Field_1101_A>
      <Field_1101_B>112</Field_1101_B>
    </Struct1101>
    <Struct1102>
      <Field_1102_A>ZS</Field_1102_A>
      <Field_1102_B>222</Field_1102_B>
    </Struct1102>
  </Struct_11>
  <Struct_22>
    <Struct2201>
      </Field_2201_A>
      </Field_2201_B>
    <Struct2202>
      </Field_2202_A>
      </Field_2202_B>
</Main>
Target
<result>
  <row>110</row></result>
<result>
  <row>#void#</row></result>
<result>  <row>112</row></result>
<result> is mapped to <Struct_11>, so that for each <Struct_11>, one <result> is created.
I've insert this sample payload and in the Definition tab, Display Queue option shows me the right result:
110
#void#
112
However, during the MM test, it throws error:
Cannot create target element /ns0:MT_TARGET/result[2]/row. Values missing in queue context. Target XSD requires a value for this element, but the target-field mapping does not create one. Check whether the XML instance is valid for the source XSD, and whether the target-field mapping fulfils the requirement of the target XSD
Any clue?
Thank you !
Edited by: rvsilvax on Sep 14, 2011 9:00 PM