Join Vaadin Dev Day in Berlin

Vaadin DevDay

 

What should my application architecture look like, so that it scales when my application’s userbase grows? What would be the best way to learn about the best practices with Vaadin? How about if we already have a large team working on Vaadin and we want to minimize boilerplate?

The way to learn the answers to these questions has previously been to build dozens of projects with Vaadin. Not anymore! We’re happy to announce Vaadin Dev Day – a one-day workshop where you’ll learn the best practices from how to bind data to your Vaadin UI to how to optimize your client-side, from the most experienced Vaadin Experts the world has to offer.

Vaadin Dev Day is hosted in Berlin, Germany on May 24th 2016 – your unique opportunity to build better maintainable applications and leverage Vaadin to the max.

The topics for the day are:

  • Optimizing Vaadin Applications, 45min
  • Picking the right architecture, sticking to it and evolving it, 45min
  • Best practices: Binding business data to Vaadin’s components, 45min
  • Keeping business logic outside your UI, 45min
  • Supporting mobile, desktop and tablet by building impressive layout systems, 45min
  • Background threads, asynchronous communication and Vaadin: Doing it right, 45min
  • Creating Vaadin UIs without coding, in plain HTML or in WYSIWYG, 45min
  • Q&A with your specific questions 

Join Senior Vaadin Expert Peter Lehto and Vaadin Architect Petter Holmström and learn from the experience of hundreds of projects. The event will be arranged in Melia Berlin hotel, right in the heart of Berlin.

Join Vaadin Dev Day
Early bird price 590€ available until February 29th.

CUBA Studio — How we use Vaadin for our Web Development Tool

CUBA Platform is a fairly new and rapidly growing Java framework for efficient enterprise application development. A significant part of its success can be associated with its own development tool - CUBA Studio, which is Vaadin-faced to the users.

Often, to employ one or another framework, you have to leaf through hundreds of pages before you even get started with the first line in your source code. In order to minimize the barriers to entry for CUBA Platform, we have developed our own framework-aware development tool for rapid business application development - CUBA Studio. CUBA Studio provides a convenient and intuitive graphical interface to any feature of the platform, where you can create your “Hello world” CUBA application in minutes. The studio manages many common aspects of enterprise application development: data model creation, visual layout design, source code scaffolding and so on.

When we started the development of CUBA Studio, we already had built up a large quantity of experience with Vaadin in CUBA Platform, because the generic UI of the platform is also built over this framework. So, why did we choose Vaadin? In this post I will highlight the most valuable features and interesting use cases.

Pure Java for Complex UI

Since CUBA Studio is a UI-oriented application with a big codebase, it requires good readability and maintainability of its source code. With Vaadin, we can use Java for the entire application. Vaadin makes it possible to use all existing Java libraries from our UI code directly. In addition, Java enables us to inherit and extend the functionality of the framework and third party add-ons. This ability to customize and change the standard behaviour of the components brings flexibility that is fundamental to CUBA Studio.

Thanks to the API of Vaadin, we can code the UI layout simply and quickly, like we use Swing or C# WinForms.

Let’s see how we can create a dialog window of CUBA Studio with Vaadin:

final Window newProjectWindow = new Window();
newProjectWindow.setModal(true);
newProjectWindow.setCaption("New project");
newProjectWindow.setWidth(400, Unit.PIXELS);

VerticalLayout content = new VerticalLayout();
content.setSpacing(true);

// add grid with properties of a new project
GridLayout grid = new GridLayout(2, 2);
grid.setColumnExpandRatio(1, 1);
grid.setSpacing(true);
grid.setWidth(100, Unit.PERCENTAGE);
Label nameLabel = new Label("Name");
nameLabel.setWidthUndefined();
grid.addComponent(nameLabel);

// add input controls
TextField nameField = new TextField();
nameField.setWidth(100, Unit.PERCENTAGE);
grid.addComponent(nameField);
Label versionLabel = new Label("Platform version");
versionLabel.setWidthUndefined();
grid.addComponent(versionLabel);

ComboBox versionBox = new ComboBox();
versionBox.setWidth(100, Unit.PERCENTAGE);
versionBox.addItem("6.0.6");
versionBox.addItem("6.0.5");
grid.addComponent(versionBox);

// add OK and Cancel buttons
HorizontalLayout buttons = new HorizontalLayout();
buttons.setSpacing(true);
buttons.addComponent(new Button("OK"));
buttons.addComponent(new Button("Cancel"));

content.addComponent(grid);
content.addComponent(buttons);

newProjectWindow.setContent(content);
newProjectWindow.center();
// show window
UI.getCurrent().addWindow(newProjectWindow);

Let’s have a look at the result:

This code is very easy to read and modify, because of its homogeneous nature (pure Java) and it does not require HTML markup or CSS styling for the layout of the UI components on a screen.

Have a look at the screen editor in CUBA Studio to see how complex screens can be built using Vaadin. A rich set of UI components within the framework enables us to organize a workspace for our development tool, similar to traditional desktop tools. 


Screen properties


WYSIWYG Screen editor

Wide Community and Rich Set of Addons

Our choice of Vaadin was also dictated by the large community and the wide range of third party add-on visual components. You can find many useful components using Vaadin Addons Directory. Add-ons are easy to add to your Vaadin project, as Maven dependencies, or as a simple jar library. We use a couple of Vaadin add-ons in CUBA Studio. For example, CUBA Studio enables you to scaffold and code sources for entities and screens and services right from your web browser with syntax highlighting. This feature is provided by a Vaadin third party addon - AceEditor

One more addon we have used in CUBA Studio is DragDropLayouts. The Drag-And-Drop approach is used for the WYSIWIG Screen designer, as you can see in the picture below.

Simple Client-Server-Client Communication Using AJAX

Modern web applications should be responsive, fast and user-friendly. Users expect a good reaction on interactions from any IDE. This is very difficult to achieve in a web tool due to the network nature, but we can use PUSH technologies for communication with a server to increase the performance of a web UI. Vaadin enables us to use the WebSocket protocol to organize a client-server communication in case of long background processing. We use this approach a lot, for example, to index a project on Studio startup or during a web server start.

To illustrate the way of how it is used in CUBA Studio, let’s implement a simple handler for the OK button of our “New project” dialog, which executes a fake long operation in the background thread and shows a notification to a user once the long operation is completed:

buttons.addComponent(new Button("OK", new Button.ClickListener() {
   @Override
   public void buttonClick(Button.ClickEvent event) {
       grid.setEnabled(false);
       buttons.setEnabled(false);
 
       // you can use ../valo/shared/img/spinner.gif
       newProjectWindow.setIcon(new ThemeResource("img/spinner.gif"));
       newProjectWindow.setCaption("Creating new project ...");
       final UI ui = UI.getCurrent();
       Thread projectCreateThread = new Thread(new Runnable() {
           @Override
           public void run() {
               try {
                   // just emulate long project creation
                   Thread.sleep(5000);
               } catch (InterruptedException ignored) {}
 
               ui.access(new Runnable() {
                   @Override
                   public void run() {
                       newProjectWindow.close();
 
                       Notification.show("New project has been created", Type.TRAY_NOTIFICATION);
                   }
               });
           }
       });
       projectCreateThread.setName("AsyncProjectCreate");
       projectCreateThread.start();  
   }
}));

So, you don’t need to write JavaScript code and support all the tricks of different browsers. Read more about PUSH notifications in the Book of Vaadin.

Conclusion

To sum up, Vaadin became a very good fit for our product. I could go on and on telling you about the features you can get with this framework, but let me just say that “It’s better to see something once, than to hear about it a hundred times” and I invite you all to visit a live demo of CUBA Studio. The demo version is available in read only mode. To see the full power of it, you can always download it from our website.

Try CUBA Studio now

 

Community Spotlight - January 2016

Spotlight, featured image

In the end of last year, our Community Spotlights were quite focused on new add-ons published to Directory. It has been really active on that front lately as well, but this time, let’s concentrate on some of the most interesting articles and examples you have recently created.

MVP in Vaadin Spring applications

For the German speaking audience, there is again some quality content available. Dr. Stefan Reisner shares his ideas of how to use MVP pattern with Spring based Vaadin applications.

Vaadin Spreadsheet to replace Excel on your workstations?

Michael Kanis shares his experiences of using Vaadin Spreadsheet. This article is also in German, but it traslates well with Chrome to English. The interesting part in his solution is that he actually packages the whole Vaadin app as an executable JAR file for local usage. This way can replace an old Excel based solution directly with Vaadin Spreadsheet. Naturally this kind of solution also has a lot of potential to add more advanced features in the future using a real development environment.

Petstore example using Spring Boot and Vaadin

Do you remember the iconic Java EE Petstore reference application and its Spring counterpart? Igor Baiborodine has done a super cool re-implementation of Petstore with a Spring based backend and modern Vaadin UI. In case somebody is asking for a larger Vaadin reference application, this is definitely my answer in the future.

Using jOOQ from Vaadin apps

Peter Kudela has set up an example that uses jOOQ for database access and a Vaadin app that uses the jOOQ service to access the data. Lukas Eder, the founder of the jOOQ project, already gave some insights for the database integration, but if you like both jOOQ and Vaadin, join Peter to develop the example further!

More Vaadin in Kotlin stuff

A Vaadin user, book author and a well known Vaadin advocate, Nicolas Fränkel, got recently interested in an alternative JVM language called Kotlin. Last year we already  discussed about Vaadlin, a tool by Sergei Egorov, to help Vaadin usage from Kotlin applications. A recent article by Nicolas discusses just the usage of raw Kotlin, but integrates it with his old favourites, Spring Boot and Vaadin.  

Tips for Scala users

Volkan Yazici shares some tips for another alternative JVM language - Scala. His article Scala Shortcuts for Vaadin Development contains lots of practical code snippets that might be handy for Scala developers building their UI with Vaadin.