title: Angular 2 Rxjs creating action after server response
body: <p>I am a new in Angular2(and especially to RxJs library) and stacked on next step. My web site starts with a register page.
  And after the completion of of register form i have base <code>service.auth.ts</code> method register usage </p>
  
  <pre><code>     registerUser(){
          this.authService.registerUser(this.registrationForm.value)
          .subscribe((data) =&gt; {
             console.log(data);
          })
          //this line should apear after server response from backend
          console.log('AFTER SERVER RESPONSE')
          }
  </code></pre>
  
  <p>And i recieve response like this </p>
  
  <p><a href="https://i.stack.imgur.com/qLtUi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qLtUi.png" alt="enter image description here"></a></p>
  
  <p>I read some stuff about <code>flatMap</code> method in RxJs documentation and it is claimed to be alternative to default <code>Promise</code> method <code>then()</code> - but i failed to create working instance of code that acutally implements <code>flatMap</code> method for my case</p>
  
  <p>So the question is : <strong>How can i achieve result so 'AFTER SERVER RESPONSE' message appears AFTER server response?</strong> (not before as mentioned on previous screenshot)</p>