vaadin

I’ve written a lot about Vaadin. I was so enthusiastic that I wrote the first book about it (besides the Book of Vaadin), its updated edition for Vaadin 7, and a companion website. Still, I’m amazed that so many people in the JVM world never heard of it. In this post, I’d like to introduce Vaadin in the context of AJAX and SSR. Short introduction to Vaadin The beauty of Vaadin lies in its simplicity - you only write backend code. You read that well.

It’s funny how things come in sequences. Recently, on three separate occasions, I stumbled upon questions asking what people used for front-end technologies. Every time, my answer was Vaadin. Unfortunately, some places, e.g. Twitter, are too limiting to explain my answer in depth. In this blog, I’ve no such limitations. In one sentence, Vaadin is a framework to create GUI using plain Java, or any JVM-based language for that matter.

The Java EE platform is huge, and I must confess I’m not aware of every one of its API. This is also true of the Spring framework, even though I think I know more of Spring than of Java EE. Lately, I was working on the version 10 of the Vaadin framework also known as Vaadin Flow. This version introduces routes. When a path is requested, the Vaadin Servlet displays the component. Routes are created by annotating specific components with the @Route annotation.

In Vaadin, to change the components displayed on the screen, there are a few options. The most straightforward way is to use the setContent() method on the UI. The most widespread way is to use the navigator. Views managed by the navigator automatically get a distinct URI, which can be used to be able to bookmark the views and their states and to go back and forward in the browser history.

TL;DR: Vaadin was hardly SEO-friendly in the past. Not anymore, with the new Volga library. Bookmarking pages Bookmarking is as old as www itself. Being able to save an URL is part of the ADN of websites. Regarding web apps, this is somewhat different. For example, in an e-commerce webapp, while it does make sense to bookmark a specific product, bookmarking a specific step of the checkout process does not.

This week, I had an interesting question on 'How in Vaadin do you add a lang attribute to the html element?' While it’s quite easy to customize individual components on the page, the outer html tag is outside our control. In this article, I’ll describe a possible solution to this problem.

It’s no mystery that I’m a fan of both Spring Boot and Vaadin. When the Spring Boot Vaadin add-on became GA, I was ecstatic. Lately, I became interested in Kotlin, a JVM-based language offered by JetBrains. Thus, I wanted to check how I could develop a small Spring Boot Vaadin demo app in Kotlin - and learn something in the process. Here are my discoveries, in no particular order.

I’m a huge Vaadin fan and I’ve created a Github workshop I can demo at conferences. A common issue with such kind of workshops is that attendees have to prepare their workstations in advance…​ and there’s always a significant part of them that comes with not everything ready.

This is it! After 10 monts of work, my first book is out: 'Learning Vaadin' is now available at Packt and Amazon. First things first, what’s is Vaadin? Vaadin is a presentation-layer web framework that let you easily develop Rich Internet Applications. It does so by provding an abstraction over the Servlet API and by letting developers assemble components to design screens (as opposed to pages as in previous generation web frameworks).

For those of you who haven’t heard of JavaBlackBelt, it’s an e-learning community site. Once registered, users can use the site in a variety of ways: First, one can take courses on a variety of programming-related subjects.Then, one can pass exams on these subjects. Each exam is made of questions one has to anwser in a limited time frame. Passing an exam gives you knowledge points; with enough knowledge points, you get the next belt, until the fabled black belt!

One year ago, under the gentle pressure of a colleague, I tried Spring Roo. I had mixed feelings about the experience: while wanting to increase productivity was of course a good idea, I had concerned regarding Roo’s intrusiveness. I left it at that, and closed the part of my memory related to it. Now, one year later, I learned that my favourite web framework, namely Vaadin, had set their sight on a Roo plugin. That was enough for me to get back on my feet and try again.

I’m more and more comitted into Vaadin since I see so many advantages to this solution. This time, I’ve investigated how to push server data to the client. Vaadin is a general purpose framework that is wise enough not to force you to code in one way or another. Many features are available in the core distribution but many more are available in the add-ons directory. One such add-on let you add push feature to your simple application.

The more I dive into Vaadin, the more I love it: isolation from dirty plumbing, rich components, integration with portlets, Vaadin has it all. Anyway, the more you explore a technology, the bigger the chances you fall down the proverbial rabbit hole. I found one just yesterday and came up with a solution. The problem is the following: in Vaadin, application objects are tied to the session. Since I’m a Spring fanboy, it does make sense to use Spring to wire all my dependencies.