JavaFX textarea doesn't display changed value - user-interface

Question

Hello guys i'm using jdk 1.8 with NetBeans version 8 and SceneBuilder 2.2. I have files Main.fxml and MainController that have 2 tabs and a TextArea at the bottom which is supposed to print out status info.
Login.fxml is a tab which i attached to Main.fxml first tab through include in scenebuilder.
It has its own controllers and a button that need to print info to the TextArea in MainController. I can access the TextArea with FXMLLoader and change the value but it doesn't update in the UI. Let's say #FXML LogID is the TextArea in MainController and this is the code in LoginController:
#FXML
private Button btn;
#Override
public void initialize(URL url, ResourceBundle rb) {
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
try {
FXMLLoader fxmlLoader = new FXMLLoader();
fxmlLoader.setLocation(getClass().getResource("Main.fxml"));
AnchorPane pane = fxmlLoader.load();
MainController control = (MainController) fxmlLoader.getController();
new Thread(new Runnable() {
#Override
public void run() {
Platform.runLater(new Runnable() {
#Override
public void run() {
control.LogID.appendText("Hello");
System.out.println(control.LogID.getText());
//prints "hello" in console but not the ui
}
});
}
}).start();
} catch (IOException ex) {
Logger.getLogger(LoginController.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
}
Any help will be appreciated.

Answer 1

After about a week of trying everything I can I came up with a different solution.
This will update it without using FXMLLoader();
All i did was give the Login.fxml anchorpane an fx:id and kept printing getParent() to console until i got root so..
#FXML AnchorPane paneID; // In LoginController.java
//In platform.runLater i ran the bottom code
TextArea area = (TextArea) paneID.getParent().getParent().getParent().lookup("#LogID");
area.appendText("Hello\n");
first getParent was the tab content area
second tabpane
third the main anchorpane