JavaFX: loading FXML at runtime and communicating with controllers

Question

I have one container in an FXML file (let's call this the main container w/ main controller) and am trying to generate other FXML-created nodes and add them as children in the main container.

I don't think I can do this by nesting the FXML since the nodes are being added to a custom component that requires function calling. I thought I could load the nodes in the main controller's initialize but this leads to a stack overflow since the loading calls the initialize function recursively.

What's the best way to do this? I want to be able to have the main controller respond to and setup the nodes. I could

Main controller looks like:

public class MainController implements Initializable {

    @FXML
    private CardPane cardPane;
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        // setup panes
        AnchorPane importPane = new AnchorPane();
        FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("ImportPane.fxml"));
        fxmlLoader.setRoot(importPane);
        fxmlLoader.setController(this);

        try {
            fxmlLoader.load();
            cardPane.addCard(importPane);
        } catch (IOException exception) {
            throw new RuntimeException(exception);
    }

}

CardPane is the custom component class where addCard adds a node (an implementation of CardLayout).

The FXML for ImportPane is pretty much empty right now. I just have a CSS styling for the root class so I can see how it's laying out.

<?xml version="1.0" encoding="UTF-8"?>

<?import java.lang.*?>
<?import java.net.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<fx:root id="AnchorPane" prefHeight="400.0" prefWidth="600.0" styleClass="mainFxmlClass" type="AnchorPane" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.40">
    <stylesheets>
        <URL value="@view.css" />
    </stylesheets>
   <children>
      <VBox alignment="CENTER" layoutX="121.0" layoutY="38.0" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" styleClass="importPane" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
   </children>
</fx:root>

The FXML for the main component is:

<?xml version="1.0" encoding="UTF-8"?>

<?import cardPane.*?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane id="AnchorPane" prefHeight="200" prefWidth="320" stylesheets="@PHASIQAnalyzerView.css" xmlns="http://javafx.com/javafx/8.0.40" xmlns:fx="http://javafx.com/fxml/1" fx:controller="phasiqplateanalyzer.PHASIQAnalyzerController">
   <children>
      <VBox alignment="CENTER" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
         <children>
            <HBox id="buttonBar" alignment="CENTER" maxHeight="-Infinity" maxWidth="1.7976931348623157E308" minWidth="-Infinity" prefHeight="100.0" prefWidth="200.0" />
            <CardPane id="mainPane" fx:id="cardPane" maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" VBox.vgrow="ALWAYS" />
         </children>
      </VBox>
   </children>
</AnchorPane>

Answer 1

remove fx:controller="phasiqplateanalyzer.PHASIQAnalyzerController" from the FXML and use the setController() method of an FXMLLoader object (no static method call for that...)

https://docs.oracle.com/javase/8/javafx/api/javafx/fxml/FXMLLoader.html#setController-java.lang.Object-

FXMLLoader fxmlLoader =new  FXMLLoader();
fxmlLoader.setController(yourControllerClass);
fxmlLoader.load("yourFxmlFile");