title: Check if user has scrolled to the bottom in Angular 2
body: <p>What is the best practice to check if user has scrolled to the bottom of the page in Angular2 without jQuery?  Do I have access to the window in my app component?  If not should i check for scrolling to the bottom of the footer component, and how would I do that?  A directive on the footer component?  Has anyone accomplished this?</p>