title: Is It good to subscribe to an observable within another subscription handler?
body: <p>I'm using Angular2 and I have a question about what is the best way to do if I have many observables.
  Can I put subscriptions inside each other or put each one in a different method and put the results in class properties?</p>
  
  <p>Example :</p>
  
  <pre><code>ngOnInit() {
  this.route.params**.subscribe**(params =&gt; {
     if (params['id']) {
      this.load = true;
       this.batchService.getPagesOfCurrentObject(params['id'], "10", "0")
         **.subscribe**(result =&gt; {
           this.stream = result;
           if (this.stream.length &gt; 0) {
             this.stream.forEach(page =&gt; { this.batchService.getPageStreamById
             (page.pageId)**.subscribe**(pageStream =&gt; {
                let base64 = btoa(new Uint8Array(pageStream.data)
                   .reduce((data, byte) 
                      =&gt; data + String.fromCharCode(byte), ''));
                 this.pages.push(base64 );
  
               })
  
               return;
             });
           }
  
       },
         error =&gt; this.errorService.setError(&lt;any&gt;error),
         () =&gt; this.load = false
         );
     }
   });
  
   try {
     this.customer = this.sharedService.processSelect.subscription.customer;
   } catch (err) {
     return;
   }
  }
  </code></pre>