If you compare the way you override the item definitions here:
"The text, imageUrl, spriteCssClass and url fields can be changed through the datatextfield, dataimageurlfield,dataspritecssclassfield, and dataurlfield, respectively."
And the way you override it here:
hasChildren boolean property indicates whether a data item contains children that can be fetched from the server. You can either hard-code it, map it to another property, or compute it with a function:
You can see that there is no standand.
I need something like that to my project's datasouce options:
But that does not work as expected. The hasChildren made me believe that this would work.
I think it is a bug.