String evaluateField(String fieldVar, IFlow flow)
{
FieldBinder binder = m_rcontext.m_fieldBinder;
String s = binder.getFieldValue(fieldVar, flow);
if (s == null) {
binder.failed(m_err);
RenderErrors.logError(m_err, RenderErrors.UnknownFieldVar,
String.format("can't find field var '%s'", fieldVar));
s = "";
}
return s;