UMG Documentation for 4.4 Preview

How would you add buttons to a grid during runtime and still be able to identify which one you pressed them?

Like an inventory, you read from a database during runtime and add “buttons” to a grid depending on the database content.
Atm i am adding buttons with “add child” to my grid. I tried to change the actual name of the added buttons but was not able to. I also tried to identify them by write down an id number into the “Tool Tip Text”, but was only able to set the text, not read it.