title: How to trigger function from one component to another in angular2?
body: <p>I have two components componentA and componentB. Both of them are sibblings, and are children of componentMother.</p>
  
  <p>I want to make it such that when I click on a button on componentA, it triggers a function call on componentB. </p>
  
  <p>Is the way to do this using a service with an observable and having componentA emit events that componentB subscribes to or is there a better/best practice way?</p>