title: Flutter. My UI is not updated when I receive a value from a Future Function
body: <p>My problem is that when I receive information from Firestore, I see it in the console that it prints but my UI does not update. But until I press the icon that shows my screen again. The screen where my list of widgets is contained in a BottomNavigationBar.</p>
  <p>What I hope will happen with the code is that when I select the tab that will contain my screen in the BottomNavigationBar, the list of Widgets appears with the names of the DocumentIDs. Well, currently I must select the tab again so that they appear.</p>
  <p>I attach my code.</p>
  <pre><code>class PruebasVarias extends StatefulWidget {
    @override
    _PruebasVariasState createState() =&gt; _PruebasVariasState();
  }
  
  class _PruebasVariasState extends State&lt;PruebasVarias&gt; {
  
  
    List&lt;String&gt; myData        = [];
    List&lt;Widget&gt; myListWidget  = [];
  
    @override
    void initState() { 
      super.initState();
      getallDocument();
    }
  
    Future getallDocument()async{
      final QuerySnapshot result = await Firestore.instance
                                        .collection(&quot;Users&quot;)
                                        .getDocuments();
      final List&lt;DocumentSnapshot&gt; documentos = result.documents;
      documentos.forEach((data) {
        myData.add(data.documentID);
        print(myData);
      });
  
      for (int i = 0; i &lt; (myData.length); i++){
        myListWidget.add(Text(&quot;${myData[i]}&quot;));
      } 
    }
  
    @override
    Widget build(BuildContext context) {
      return  Scaffold(
        appBar: AppBar(
          backgroundColor: Colors.red,
          title: Text(&quot;Documents&quot;),
          actions: &lt;Widget&gt;[
          ],
        ),
        body: Center(
          child: 
          Column(children: myListWidget),
        )
      );
    }
  }
  </code></pre>