It should be possible to define your own no selection available logic.
Imagine you have a datagrid of questions and you want to add a button to add or insert a question.
If no selection is made, the question should be added to the end of the list and otherwise the question needs to be inserted before the selected question.
Although this logic seems pretty straightforward.
It is not possible, because the microflow that is being called by the action button requires an object or a list of objects to pass the selected item(s).
And when they are empty, Mendix shows the message below ('No selection available').
So you'll have to add two buttons and two microflows, one with selected item(s) parameter and one without. From both a UX point of view as a development/
reusability point of view this is not what you would want.
I was just running into a similar issue. It was about task creation. If a task is selected, a new task should be created for the same process. If no task is selected, the user needs to select or create a process.
It sounds that simple but is not possible. It would be awesome if “No selection” would just lead to an empty parameter, so that the developer can decide what to do.