title: Logout timer for multiple tabs in angular 4
body: <p>i have a requirement to auto logout users after a period of inactivity. I should prompt the user with a warning about the impending logout and if no activity ensues, or the prompt is not dismissed, the user should be logged out programmatically. This needs to work with multiple tabs open to the same web app, but there should only be one warning prompt. What I mean by this, is that if the user opens a tab to the web app, then opens another tab to the same web app, then after some period of inactivity, the warning prompt should appear in only one of the tabs (the first opened tab). I should also note that all tabs use the same session on the back end. Any ideas on how to implement this?
  Thanks</p>