title: How do I create a custom event in an AngularJs service
body: <p>I am working on an AngularJs project. I have a service which sets and removes events on some buttons. This service is utilized by another service which I do not want to interact directly with the buttons. However I would like a button click event to be filtered up through the first service and handled in the second one. Since I don't want the second service to be aware of the buttons, I figure I will need to create a custom event in the first service. How can I create a custom event and fire it when a button is clicked? </p>
  
  <p>Thanks in advance.</p>