fx:context attribute

The default binding context is the root element of the FXML document. This can be changed with the fx:context attribute, which can be set to an arbitrary object. Binding expressions will then be resolved against the object referenced by fx:context.

The fx:context attribute can only be set on the root node of the FXML document.

Static object in element notation

The value of fx:context can be a static object that is instantiated in the FXML document with element notation. The object exists outside of the scene graph and is internally stored by the root node.

<StackPane xmlns="http://javafx.com/javafx" xmlns:fx="http://jfxcore.org/fxml/2.0">
    <fx:context>
        <!-- Instantiate MyBindingContext and set it as the control's binding context -->
        <MyBindingContext/>
    </fx:context>

    <!-- "user.name" will be evaluated against MyBindingContext -->
    <Label text="${user.name}"/>
<StackPane/>

class MyBindingContext {
    ObjectProperty<User> userProperty();
    ...
}

class User {
    StringProperty nameProperty();
    ...
}

Binding path to an object

The binding context may also be exposed with a field, getter, or ObservableValue on the code-behind class. In this case, the value of fx:context is a binding path.

com/sample/MyControl.fxml

<StackPane xmlns="http://javafx.com/javafx" xmlns:fx="http://jfxcore.org/fxml/2.0"
           fx:class="com.sample.MyControl"
           fx:context="$myContext">
    <!-- "user.name" will be resolved against "myContext" -->
    <Label text="${user.name}"/>
<StackPane/>

com/sample/MyControl.java

public class MyControl extends MyControlBase {
    final MyBindingContext myContext;

    MyControl() {
        myContext = new MyBindingContext();
        initializeComponent();
    }
}

class MyBindingContext {
    ObjectProperty<User> userProperty();
    ...
}

If the binding context object can change and is exposed as an ObservableValue, the fx:context attribute can be bound with a unidirectional binding. Note that this will incur listener management overhead. If possible, a one-time assignment should be preferred.