javafxfxml

JavaFX FXML, sometimes referred to as javafxfxml, is an XML-based markup language used to define the user interface of JavaFX applications. It separates UI layout from application logic, enabling designers to work on the presentation while developers implement behavior in Java.

An FXML document describes a scene graph. The root element corresponds to a JavaFX layout pane, such as VBox, HBox, GridPane, BorderPane, or StackPane, with child nodes for controls and containers. The document declares the fx:controller attribute to specify the controller class. Components can declare fx:id attributes to allow the FXMLLoader to inject corresponding fields in the controller annotated with @FXML.

Event handling is performed through attributes like onAction on nodes, which reference methods in the controller. The FXMLLoader parses the file, creates the UI components, injects dependencies, and constructs the scene graph, which can then be attached to a scene and stage. FXML also supports custom components and nested controllers, and can be used with a controller factory for dependency injection.

XML namespaces are declared at the top of the document, typically including xmlns:fx for the FXML namespace and xmlns for the JavaFX component namespace. Example namespaces may vary by version.

Usage and ecosystem: FXML is part of the JavaFX framework. It offers benefits such as separation of concerns, clearer collaboration between UI designers and developers, and easier internationalization and styling via CSS. Limitations include the need to learn the markup and potential runtime errors when the FXML does not align with the controller or model. FXML works best when used for static or semi-static UIs, with dynamic behavior written in Java or another supported language.