How to select all the TreeGrid rows using a custom button click

In TreeGrid, with checkbox row selection enabled, it is possible to select all the rows using a custom button click instead of the default column header checkbox. By calling the selectAllRows public method in the button click action, user can able to able to toggle between selecting and unselecting the rows in TreeGrid.

Please find the code snippet below,

You can able to find the sample for this use case here.