Vaadin Flow 1.3.0.alpha2 is a pre-release for the next minor Flow version.

Vaadin Flow 1.3.0.alpha2

Flow is a new Java web framework for creating UIs using Java or HTML. Flow handles everything related to communication between client and server and makes it possible to create UIs using the desired abstraction level you choose. It has all the capabilities you need to build a modern web app: from high level APIs for structuring your applications and binding data to it, into taking full control over the DOM and communication with HTML templates.

Flow is a part of the Vaadin platform. For information and helpful resources like documentation and examples on Vaadin Flow, please visit the Flow page vaadin.com/flow.

The complete documentation can be found here

New Features in 1.3. (Since 1.2)

Alpha2:

• Dynamic route registration support (#4829) (see documentation)
• Implement forwardTo to BeforeEvent (#4867)
• Add property sync to DomListenerRegistration (#4773)
• Register built-in bundle dependency filters last (#4878)

Alpha1:

• Possibility to enable Brotli compression #4583
• Add helpers for wrapping UI.access callbacks #4742
• Anchor: add constructor that accepts a list of components #4775
• Added more helper methods for HasSize #4811
• Provide String constants for common @Viewport settings #3597
• Add IFrame component #4783

Dependency updates since 1.3.0.alpha1

• Bump jackson-databind version (#4930)

Bug Fixes Since 1.3.0.alpha1

• Make filter related methods work properly for hierarchical DP (#4846)
• Make the DataCommunicator ask for new sizes when the DataProvider return less items than expected (#4889)

See complete list of changes since 1.3.0.alpha1

Other notable changes since 1.2

Internal class RouterUtil has been renamed to RouteUtil and some unused code will be removed from it in an later alpha release. As this class is in an internal package, you should not be using it in your Flow applications.

Supported Technologies

See the Vaadin platform release notes for browser, server and Java support level.

Known Limitations

• Template-in-Template feature has some limitations

Work in progress

• Dynamic routing #3913
• Keyboard shortcuts API #2449

Flow 1.3 Feature Highlights

Using Components to build UIs with only Java

With Flow you to can compose UIs using only Java on the server side. You can use existing components or create your own by creating the DOM from the server side. See the relevant documentation:

• Using Vaadin Components
• Creating New Components and the Element API

Integrating Web Components

Flow allows you to integrate web components and consume them from server side Java. See the web components documentation for more information.

Router

Router is a core concept in Flow, enabling navigation for your website or web app. It is based on HTML5 History API, and makes it possible to for the user to navigate pages back and forward, and keep the page state intact. See the router documentation for more information.

Binding Data to Components

Flow allows you to easily bind your business data to the UI components. You can bind the forms to the business objects by using the Binder, see documentation for more information. For showing a list of data (eg. a database table) on the UI, you can use the DataProvider. See documentation for more information.

Creating UIs Declaratively with Polymer Templates

With Flow you can take full control of building the DOM and the communication by using HTML templates. We recommend using Polymer templates as they bring lots of helpful capabilities on top of the native HTML. See documentation for more information.

Theming Applications

Flow has support for customizing the look and feel of your applications with css, html custom styles or by customizing the ready made Themes provided for Vaadin Components. See the documentation for more information.

Spring Integration

Flow comes with a Spring integration, and you can use it with Spring 5 or Spring Boot 2. Please see the documentation for more information.

JavaEE / JakartaEE Integration (CDI)

Flow support Java Context and Dependency Injection (CDI) with an add-on. Please see the documentation for more information.

Getting Started

For getting started with Vaadin Flow, please see vaadin.com/start for different available examples. All the projects bring the Flow dependency via the Vaadin platform, which is the recommended way for using Flow.

From Flow getting started documentation you can find a step-by-step tutorial.