During these tutorials we will be solving a number of common problems when using the Vaadin CDI plugin. The principal question we will be addressing is "How do I gain access to CDI features in a Vaadin project?"
At the end of these tutorials you will have learned how to
Set up a Vaadin CDI project
Create UI’s and Views with Vaadin CDI
Use injection with standard and Vaadin CDI scopes
Pass events between various parts of your application
Set up access control for your application
We will assume familiarity with Vaadin 7 and common CDI concepts. As a reference development environment we’ll be using Eclipse Luna with the Vaadin plugin, Maven and TomEE. Installation and configuration of said environment is outside the scope of these tutorials.
The tutorials will build off one another, each starting where the previous left off. If you wish to jump in at a later point feel free to get a copy of the project here: https://github.com/Vaadin/cdi-tutorial. The repository has tags for each tutorial’s starting point, called tutorial-1 to tutorial-5.
If you are eager to get started right away without following the tutorial, feel free to do so. There are still some practical details that are good to keep in mind if you’re not familiar with Vaadin CDI features or CDI in general.
Use TomEE Web Profile or some other JavaEE 6+ server. Tomcat or Jetty won’t work out of the box.
Add the JavaEE API to your classpath if e.g. the @Inject annotation can’t be found. Depending on how your project is configured, this might not be necessary and might in some cases even cause conflicts.
Objects must be injected and managed by the CDI implementation in order to use CDI features.
Use @Inject on an instance field to make the CDI implementation inject a managed instance of the corresponding type.
Annotate your UI class with @CDIUI("") to let Vaadin CDI know that it should inject and use instances of that class when the application is opened in the browser.
Remove any existing VaadinServlet from your project (look for servlets with @WebServlet or defined in web.xml). Vaadin CDI has its own VaadinCDIServlet that will be deployed automatically as long as no other Vaadin servlets are present.
Initialize objects in a method annotated with @PostConstruct. CDI features such as @Inject are not yet functional when the constructor is run.