title: Angular 2 executing observables in a series
body: <p>I have the following method:</p>
  
  <pre><code> getProject(name) {
    this.ProjectName = name;
    //Friendly URL to ID --&gt; FIRST OBSERVABLE
     this.af.database.object('/friendly_urls/' + name).take(1).share().map((data) =&gt; {
      //ID to data --&gt; SECOND OBSERVABLE
       this.af.database.object('/Project/' + data.$value).take(1).map((ProjectData) =&gt; {
         console.log("Received Project data");
        this.ProjectData = ProjectData;
      });
    },
    error =&gt;  {
      console.log(error);
      /* TODO: Permission blocked page */
      this.router.navigate(['']);
    });
  }
  }
  </code></pre>
  
  <p>I have 2 observables: The first observable, which executed first, and second one - which is executed right after him.</p>
  
  <p>I tried to understand how to use <a href="http://www.syntaxsuccess.com/viewarticle/combining-multiple-rxjs-streams-in-angular-2.0" rel="nofollow">this</a> in my case and couldn't figure it out.</p>
  
  <p>How I can execute this observables in a series without observable inside observable? </p>