SmartGWT data retrieval with complex XML/JSON

I've been using SmartGWT's data source to fetch data from a web service and put it into a ListGrid. This has worked well because there were no sub elements. However, now I have an XML structure as follows:

<persons>
<person>
    <field1>blah</field1>
    <field2>blah2</field2>
    <tests>
        <test>
            <testName>name</testName>
            <testValue>value</testValue>
        </test>
    </tests>
    <answers>
        <answer>
            <answerField>blah</answerField>
            <answerField2>blah2</answerField2>
        </answer>
    </answers>
</person>

How would I use a datasource to put the person fields in one list grid, the test sub elements in another, and the answer sub elements in yet another? There's nothing like setSubRecordXPath and I don't see how using the value XPath would allo开发者_C百科w me to retrieve the data I need either. I also don't see how I could use multiple data sources.

Could someone show me how to do this or point me to a resource? The SmartGWT Showcase examples were all of a relatively simple structure (that I saw).

If it matters, I do have access to JAXB annotated classes that represent these various fields but I wouldn't know how to use them within the SmartGWT framework.

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You can override the execute method of DSCallback when calling the data source's fetchData method. Basically I use getAttributeAsRecordArray on those things that are supposed to be logical records. Still working on it but it's looking promising so far.