Hi Ralf,
I’m sorry to tell you that it’s not going to work out the way you want it to.
UI5 doesn’t provide any way to access the current element or its properties in expression/property bindings, since they are included in the View.json.
If you just don’t want to use your USER_Struct variable for the binding, a possible alternative could be to write the values of the selected property of each checkbox into a view model and then reference the model path in the binding of the key property of the respective checkbox in the UI Designer. For this you need to take care of initializing the view model first though.
If you want to have an example of the ‘ViewModel’ solution, I’ll be happy to provide you with one.
As another option you could add a formatter function to the property binding of ‘selected’ for each checkbox but again, this would rely on scripting and usage of model binding.
Regards,
Vitali