title: Access property from component in provider in angular2
body: <p>So I'm new to OOP and trying out ionic 2 with angular 2 with typescript.
  Say I have an input in the home.html file that is coupled to username in home.ts like this:</p>
  
  <pre><code>export class HomePage {
  public username: string;
  public newusername: string; 
  ...
  constructor(public users: UserService) {
  ...
  </code></pre>
  
  <p>Now I want a service (userService.ts) to take username from the input or home.ts and modify it and store the result as newusername.</p>
  
  <p>Do I have to make a constructor in the service/provider like in Homepage which instantiates a new object of home though I already made an object of this in home.ts? </p>
  
  <p>I imported HomePage in userServices but I cant access newusername because I didnt make an object of it.</p>