title: Mixed data from two promises
body: <p>I have 2 services that return 2 promises, the first service return a list of objects, the second one returns the details for each object based on the id. So I need to invoke <code>service2</code> for each object returned from <code>service1</code>.
  The loaded data will be saved in an array;</p>
  
  <p>This is the way that I implemented but doesn't work</p>
  
  <pre><code>objects: object[];
  
  service1.then(res =&gt; 
       objects = res.data;
       objects.forEach( obj =&gt;
           loadService2(objId,(dtObj) =&gt; {obj = dtObj})
       )
  );
  
  loadService2(obj: object, callback: (detailsObject: DtlObject) =&gt; void){
      service2.then(res =&gt; callback(res.data););
  }
  </code></pre>
  
  <p>This solution not work. After I still have the array of objects without details.</p>