title: How to modify a Label from another Controller (lookup + update)?
body: <p>I have created a tabPane. Under each tab, I have included () an fxml to show the actual session user, with this code :</p>
  
  <p>home-tab.fxml has this line :</p>
  
  <pre><code>&lt;fx:include fx:id="topTab" source="../top-tab.fxml"/&gt;
  </code></pre>
  
  <p>top-tab.fxml :</p>
  
  <pre><code>&lt;AnchorPane maxHeight="20.0"  prefWidth="600.0" xmlns:fx="http://javafx.com/fxml" fx:controller="wuendo.client.TopTabController"&gt;
     &lt;children&gt;
        &lt;HBox id="hbox_top" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0"&gt;
           &lt;Label id="label_session" prefHeight="20.0" text="SESSION : " /&gt;
           &lt;Label fx:id="sessionLabel" prefHeight="20.0" text="" /&gt;  
        &lt;/HBox&gt;
     &lt;/children&gt;
  &lt;/AnchorPane&gt;
  </code></pre>
  
  <p>TopTabController.java :</p>
  
  <pre><code>@FXML public Label sessionLabel;
  </code></pre>
  
  <p>HomeTabController.java :</p>
  
  <pre><code>@FXML private TopTabController topTabController;
  
  
  @Override
  public void initialize(URL url, ResourceBundle rb) {
  
    URL location = getClass().getResource("../top-tab.fxml");
    FXMLLoader fxmlLoader = new FXMLLoader(location);
    AnchorPane root = null;
    try {
       root = (AnchorPane) fxmlLoader.load();
    }  catch (IOException ex) {
       Logger.getLogger(HomeTabController.class.getName()).log(Level.SEVERE, null, ex);
    }
    topTabController = (TopTabController) fxmlLoader.getController();
  
    Label txt = (Label) root.lookup("#sessionLabel");
    txt.setText("blabla");
  
    System.out.println("sessionLabel= " + topTabController.sessionLabel.getText());
  }
  </code></pre>
  
  <p>When I execute this, the console prints "blabla", but the label is not modified in the program (gui)</p>
  
  <p>What do I have to do to see the value updated ?</p>
  
  <p>Thank you all</p>