title: Call method between independent components using BehaviorSubject in Angular 4+
body: <p>What is the best practices for calling a method between independent (no parent-child relation) components? I have a look at several samples on the web i.e. but some of them use BehaviorSubject, some of them Observable, and some of them lack of completing observables with ngOnDestroy() method. There is an example usage on <a href="https://stackoverflow.com/questions/48069554/how-to-execute-a-function-from-another-component-that-is-not-a-sibling-of-the-fi">How to execute a function from another component that is NOT a sibling of the first component?</a> that I can apply to my Angular7 project successfully, but I think there is a better approach using BehaviorSubject without any missed point. Any idea? </p>