Hello Oleg,
thanks for your answer, I know this. functionality.
But I do not have the option to pass an URL, I have to query my data by an jQuery AJAX Request.
I pass the parent ID and get some JSON data. On client side I am updating the data array.
It is working if I use the onRowSelected event, but I do not retrieve an event clicking on the expand symbol.
I hope you can understand my problem, it is by design of our complete architecture.
Greetz
Chico