Fill repeated grid by http service/Action in orbeo

问题:

I'm trying to fill a repeated grid in orbeon with a XML file and http service/action. The xml looks like this:

<result>
    <code>Row 1</code>
    <code>Row 2</code>
    <code>Row 3</code>
</result>

But only the first row is filled and no row is dynamically added to repeated grid. What step is missng?

Thx!

Best regards, Alex