fx:id attribute

The fx:id attribute is used to name elements in an FXML document. If the document has a code-behind class, the FXML compiler generates a protected field with the same name to make the named element accessible from Java code.

The fx:id attribute also sets the Node.id property to the same value.

Usage

com/sample/MyControl.fxml

<StackPane xmlns="http://javafx.com/javafx" xmlns:fx="http://jfxcore.org/fxml/2.0"
           fx:class="com.sample.MyControl">
    <Button fx:id="myButton1"/>
</StackPane>

com/sample/MyControl.java

public class MyControl extends MyControlBase {
    MyControl() {
        initializeComponent();

        // The named element "myButton1" can be referenced in the code-behind class.
        // Note that the value of "myButton1" is set by initializeComponent(), so it is
        // only available after the method was invoked.
        myButton1.setText("My Button");
    }
}