title: How to update dependency injection token value
body: <p>Angular dependency injection let you inject a string, function, or object using a token instead of a service class. </p>
  
  <p>I declare it in my module like this:</p>
  
  <pre><code>providers: [{ provide: MyValueToken, useValue: 'my title value'}]
  </code></pre>
  
  <p>and I use it like this:</p>
  
  <pre><code>constructor(@Inject(MyValueToken) my_value: string) {
    this.title = my_value;
  }
  </code></pre>
  
  <p>However, how can I update the value from the component and let other components get every time the new value? in other words, I want to simulate the functionality of using something like a <code>BehaviorSubject</code> to emit and receive values.</p>
  
  <p>If this is not possible then what is the use of those injection tokens values if they provide only static data as instead I can simply declare the static value in my component and use it directly.</p>