Embedded markup

FXML 2.0 markup can be embedded directly into Java or Kotlin source code with the @ComponentView annotation. This can be useful for custom controls and reusable components that benefit from keeping markup and imperative logic in the same file.

The @ComponentView annotation is available in the markup library.

The annotated class supplies the markup source text, and the compiler treats it like a regular FXML view associated with that component:

package com.sample;

import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import org.jfxcore.markup.ComponentView;

@ComponentView("""
    <StackPane>
        <Button fx:id="myButton"/>
    </StackPane>
""")
public class MyControl extends MyControlBase {

    public MyControl() {
        initializeComponent();
        myButton.setText("Hello!");
    }
}

How embedded markup differs from standalone files

Embedded markup follows the same language rules as standalone FXML, but some information is provided by the surrounding Java or Kotlin source:

• The annotated class is already known to be the code-behind class, so the fx:subclass attribute is neither required nor supported.
• Import declarations from the Java or Kotlin source file are also available to the embedded FXML document, they do not need to be redeclared as <?import?> processing instructions.
• The xmlns="http://javafx.com/javafx" and xmlns:fx="http://jfxcore.org/fxml/2.0" namespaces are implied and do not need to be explicitly declared.

The generated base class still follows the usual naming convention, so MyControl extends MyControlBase. This can be changed with the fx:className attribute.

In Kotlin projects, the embedded FXML document cannot reference type aliases.

Enable annotation processing

The @ComponentView annotation is processed at compile time by an annotation processor, it is not retained in the compiled class file. The FXML 2.0 Gradle plugin does not enable annotation processing by default, you need to opt in explicitly in your Gradle build script:

fxml {
    annotationProcessing = true
}

In Kotlin projects, the KSP plugin also needs to be explicitly applied:

plugins {
    kotlin("jvm") version "2.3.20"
    id("com.google.devtools.ksp") version "2.3.6"
    id("org.jfxcore.fxmlplugin") version "0.13.0"
}