Uploads and downloads, inputs and outputs

Vaadin Upload asks the developer to provide an OutputStream where the framework can stream the file content. Vaadin StreamResource (~ download) asks the developer to provide an InputStream the framework can read and stream to a user. Intuitive? Not really, unless you have accustomed to this inversion during your Vaadin career.

Testing the UI without a browser

Martin Fowler has introduced a metaphor Test Pyramid, to suggest that you should only write a fraction of end-to-end tests compared to small unit tests. It is not because end-to-end tests, like the ones using Vaadin TestBench or Selenium, are worse. They are actually better as they test all parts ...

Vaadin at Oracle CodeOne San Francisco

Next week it's time for the biggest Java developer event of the year: CodeOne. The conference, previously called JavaOne, is a great chance to catch up with other developers and learn about what's new in the Java community. Since last year, we have released a ton of new stuff: Vaadin 10 and 11 ...

Get to Know the Vaadin Teams - Flow Team

Meet the Flow Team, nicknamed the Flowers. They are developing the server-side Java web framework, Vaadin Flow, which replaces Vaadin Framework. The Flow Team helps the community by developing open source products and answering questions from users on vaadin.com/forum and gitter.im/vaadin/flow. The ...

V8 vs. V10 - two maintained Vaadin versions, which one to choose?

Are you the one who jumps in to try all new technology? When choosing your car model, do you already select a hybrid engine, or even a fully electric one, instead of the conventional combustion engine? Both will take you from location A to place B, but features and risks in your investment are ...

Master the basics of Vaadin 10 Platform

Simplifying web application development has always been a priority for Vaadin, as epitomized by our “Fight for simplicity” motto. With the introduction of Vaadin 10, we offer a platform that you will continue to benefit from as you have used to since the early days of Vaadin. To make it easier for ...

Vaadin 10 is out!

The wait is over. We're happy to announce the release of Vaadin 10! Vaadin 10 is the largest update in the history of Vaadin. We have rewritten both the components and communication layer. Vaadin 10 allows you to better take advantage of everything in the modern web platform, all while maintaining ...
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Using a WebAssembly Module with Vaadin Flow

Utilizing WebAssembly modules (WASM) increase the performance and efficiency of a web application. With Vaadin Flow, loading a WASM can be as simple as writing the proper fetch statement in one of your Polymer templates. Flow also allows developers to easily control the use of these modules from ...

Stability in production – Bleeding edge in development

We have been thinking hard about how to bring more value with our products. A part of the solution is the Vaadin platform itself; what features and tools we add. Another major part is how that value is delivered. Us developers can be divided roughly into two groups. To those of us who value ...

Vaadin's frontend direction

There has been some discussion about what the recently announced Vaadin 10 platform means in the context of GWT. I'll summarise some background about the direction we're taking here. I want to bring up two central themes: component models and freedom of choice. Component models UI development ...