Executing controller's method from another controller - on save -> refresh corresponding table

Question

Departments controllers are loaded from SceneWithButtonsController. StageAddController is loaded from LayoutWithHomeAndAddController. I want to execute this method from StageAddController which executes corresponding method from departments controller :

//Show Stage to add a worker

public class LayoutWithHomeAndAddController {
    @FXML
    private void addButtonClicked() throws IOException{
        FXMLLoader loader = new FXMLLoader();
        loader.setLocation(getClass().getResource("/views/StageAdd.fxml"));
        BorderPane addWorkerPane = loader.load();

        StageAddController stageAddController = loader.getController();


        Stage stageAdd = new Stage();
        stageAdd.setTitle("Add New Worker");
        stageAdd.resizableProperty().setValue(Boolean.FALSE);
        Scene scene = new Scene(addWorkerPane);
        scene.getStylesheets().add("/css/redBorder.css");
        stageAdd.setScene(scene);
        stageAdd.initModality(Modality.WINDOW_MODAL);
        Stage mainStage = (Stage) root.getScene().getWindow();
        stageAdd.initOwner(mainStage);
        stageAdd.show();}
}

Controller class where departments are loaded:

public class SceneWithButtonsController {


//Show workers from Mechanical Department
   @FXML
    private void mechanicalDepartmentButtonClicked() throws IOException {
       FXMLLoader loader = new FXMLLoader();
       loader.setLocation(Main.class.getResource("/views/MechanicalDepartment.fxml"));
       BorderPane mehOdjel = loader.load();
       MechanicalDepartmentController mechanicalDepartmentController = loader.getController();
       mechanicalDepartmentController.populateTable();
       BorderPane borderPane = (BorderPane) pane.getParent();
       borderPane.setCenter(mehOdjel);

    }

    //Show workers from Electrical Department
    @FXML
    private  void electricalDepartmentButtonClicked() throws IOException {
        FXMLLoader loader = new FXMLLoader();
        loader.setLocation(Main.class.getResource("/views/ElectricalDepartment.fxml"));
        BorderPane elOdjel = loader.load();
        ElectricalDepartmentController electricalDepartmentController = loader.getController();
        electricalDepartmentController.populateTable();
        BorderPane borderPane = (BorderPane) pane.getParent();
        borderPane.setCenter(elOdjel);

    }
}

StageAddController:

public class StageAddController {

private ElectricalDepartmentController electricalDepartmentController;
    private MechanicalDepartmentController mechanicalDepartmentController;

    public void setElectricalDepartmentController(ElectricalDepartmentController electricalDepartmentController) {
        this.electricalDepartmentController = electricalDepartmentController;
    }

    public void setMechanicalDepartmentController(MechanicalDepartmentController mechanicalDepartmentController) {
        this.mechanicalDepartmentController = mechanicalDepartmentController;
    }


public void refreshTableOnSaveButtonClicked() {
    if (departmentBox.getValue().equals("Electrical")) {        
        electricalDepartmentController.refreshButtonClicked();
    }
    else if(departmentBox.getValue().equals("Mechanical")) {
        mechanicalDepartmentController.refreshButtonClicked();
    }
}
}

This means that refreshButtonClicked() method from ElectricalDepartmentController or MechanicalDepartmentController will be executed.

ElectricalDepartmentController (same is with MechanicalDepartmentController):

public class ElectricalDepartmentController {

public void initialize() throws IOException {
        StageAddController stageAddController = new StageAddController();
        stageAddController.setElectricalDepartmentController(this);
        workersTableColumn.setCellValueFactory(new PropertyValueFactory<>("nameSurname"));
        rowSelected();
    }
 @FXML
    public void populateTable() {
        for(Worker worker : workerDao.getWorkersNameSurname("Electrical")) workersList.addAll(worker);
        workersTable.setItems(workersList);
    }

@FXML
    public void refreshButtonClicked() {
        workersList.removeAll(workersList);
        populateTable();
    }
}

How to achieve this.

Answer 1

You need to link controllers. In order to do that, when loading the respective FXML for the subordinate form, you have to set the parent controller for it manually so that you can have access to it.

Unfortunately, FXML does not provide a native way to link controllers. What you want to do is you want to use the full FXMLLoader functionality (instead of using FXMLLoader.load()), since the FXMLLoader also has a getController() method. It's probably a wise idea for your controllers to implement something like this:

public interface HierarchicalController {
    HierarchicalController getParentController();
    void setParentController(HierarchicalController controller);
}

EDIT: Component preload code:

public class SceneWithButtonsController {

   protected FXMLLoader<?> mechanicalLoader;
   protected FXMLLoader<?> electricalLoader;
   protected BorderPane mechanicalPane;
   protected BorderPane electricalPane;

   public void initialize() {
       mechanicalLoader = new FXMLLoader(Main.class.getResource("/views/MechanicalDepartment.fxml"));
       mechanicalPane = loader.load();
       MechanicalDepartmentController mechanicalDepartmentController = loader.getController();
       mechanicalDepartmentController.populateTable();

       electricalLoader = new FXMLLoader(Main.class.getResource("/views/MechanicalDepartment.fxml"));
       electricalPane = loader.load();
       ElectricalDepartmentController electricalDepartmentController = loader.getController();
       electricalDepartmentController.populateTable();

       // now what is the relation between StageAddController and SceneWithButtonsController ?

   }

   //Show workers from Mechanical Department
   @FXML
    private void mechanicalDepartmentButtonClicked() throws IOException {
       BorderPane borderPane = (BorderPane) pane.getParent();
       borderPane.setCenter(mechanicalPane);

    }

    //Show workers from Electrical Department
    @FXML
    private  void electricalDepartmentButtonClicked() throws IOException {
        BorderPane borderPane = (BorderPane) pane.getParent();
        borderPane.setCenter(electricalPane);

    }
}