Instructor: Import the fromEvent operator from RxJS. Next, create an observable using the fromEvent operator that listens to the entire document for a click event. Subscribe to the observable and pass in an observer that logs out each event. Now we can click on the document and see our event stream.
If we change our observer to just type out clicked, we'll see similar behavior. Now, we can use document.getElementsByTagName to access the button on our page. We can then listen for clicks directly on the button. As we can see, this is similar to fromEvent listener, but using an observable.