A tip about the use of Fullscreen Dialog when blocking a user’s access to functionality:
Since a dialog is just a popup window positioned above the existing HTML content, it is possible to delete this from the HTML content tree via the browser development area, through right click→Inspect. When using a Fullscreen Dialog to block access, a user theoretically has the opportunity to remove this dialog and “hack” their way into the system. See the attached screen recording for a (totally real) example.
It is therefore better to use a View for this functionality, and not a Fullscreen Dialog. You can use an On View Load or On App Load action which navigates to the “No Access” view if the user is missing the correct roles.
(Everyone here would of course also filter the data in the app if the user was missing the correct access, but this is useful to know either way 
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