JavaFX pass values from child to parent

Question

I have one parent controller which contain one button. When I click on button it open new window and show some data into table. The code I have used for opening window is

Answer 1

Expose a property in your child controller and observe it from the "parent" controller. There isn't really enough information in your question to give a precise answer, but it would look something like:

public class ChildController {

    @FXML
    private TableView customerTable ;

    private final ReadOnlyObjectWrapper currentCustomer = new ReadOnlyObjectWrapper<>();

    public ReadOnlyObjectProperty currentCustomerProperty() {
        return currentCustomer.getReadOnlyProperty() ;
    }

    public Customer getCurrentCustomer() {
        return currentCustomer.get();
    }

    public void initialize() {
        // set up double click on table:

        customerTable.setRowFactory(tv -> {
            TableRow row = new TableRow<>();
            row.setOnMouseClicked(e -> {
                if (row.getClickCount() == 2 && ! row.isEmpty()) {
                    currentCustomer.set(row.getItem());
                }
            }
        });

    }
}

and then you just do:

Stage stage = new Stage();
FXMLLoader fxmlLoader = new FXMLLoader(
        getClass().getResource("../layout/SearchCustomer.fxml"));
Parent parent = (Parent) fxmlLoader.load();

ChildController childController = fxmlLoader.getController();
childController.currentCustomerProperty().addListener((obs, oldCustomer, newCustomer) -> {
    // do whatever you need with newCustomer....
});

Scene scene = new Scene(parent);
stage.initModality(Modality.APPLICATION_MODAL);
stage.initOwner(parent.getScene().getWindow());
stage.setScene(scene);
stage.resizableProperty().setValue(false);
stage.showAndWait();

An alternative approach is to use a Consumer as a callback in the child controller:

public class ChildController {

    @FXML
    private TableView customerTable ;

    private Consumer customerSelectCallback ;

    public void setCustomerSelectCallback(Consumer callback) {
        this.customerSelectCallback = callback ;
    }

    public void initialize() {
        // set up double click on table:

        customerTable.setRowFactory(tv -> {
            TableRow row = new TableRow<>();
            row.setOnMouseClicked(e -> {
                if (row.getClickCount() == 2 && ! row.isEmpty()) {
                    if (customerSelectCallback != null) {
                        customerSelectCallback.accept(row.getItem());
                    }
                }
            }
        });

    }
}

And in this version you do

Stage stage = new Stage();
FXMLLoader fxmlLoader = new FXMLLoader(
        getClass().getResource("../layout/SearchCustomer.fxml"));
Parent parent = (Parent) fxmlLoader.load();

ChildController childController = fxmlLoader.getController();
childController.setCustomerSelectCallback(customer -> {
    // do whatever you need with customer....
});

Scene scene = new Scene(parent);
stage.initModality(Modality.APPLICATION_MODAL);
stage.initOwner(parent.getScene().getWindow());
stage.setScene(scene);
stage.resizableProperty().setValue(false);
stage.showAndWait();