title: How to wait for return value and subscribe to it in Angular2?
body: <p>I've encountered a problem while developing app in Ionic. I'm executing a query on the database using database provider and it is fine but it is probably called asynchronous because I get undefined.</p>
  
  <p>After some checks and other logic I'm returning value from the database:</p>
  
  <pre><code>this.databaseProvider.getValueFor(saved.id)
      .then(data =&gt; {
             return data;
      });
  </code></pre>
  
  <p>Is there any way to return data to Observable and subscribe to it? I'm quite new to Angular2 and don't know all concepts.</p>