vaadin-framework/documentation/articles/VaadinCDI.asciidoc

---
title: Vaadin CDI
order: 47
layout: page
---

[[vaadin-cdi]]
= Vaadin CDI

During these tutorials we will be solving a number of common problems
when using the https://vaadin.com/directory/component/vaadin-cdi[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

1.  Set up a Vaadin CDI project +
2.  Create UI's and Views with Vaadin CDI +
3.  Use injection with standard and Vaadin CDI scopes +
4.  Pass events between various parts of your application +
5.  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
http://www.eclipse.org/downloads/[Eclipse] Luna with the
http://marketplace.eclipse.org/content/vaadin-plugin-eclipse[Vaadin
plugin], Maven and http://tomee.apache.org/apache-tomee.html[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.

[[vaadin-cdi-for-the-impatient]]
Vaadin CDI for the impatient
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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
https://vaadin.com/directory/component/vaadin-cdi[Vaadin CDI features] or CDI in
general.

* *Use http://tomee.apache.org/downloads.html[TomEE Web Profile]* or
some other JavaEE 6+ *server*. Tomcat or Jetty won't work out of the
box.
** *Add the http://mvnrepository.com/artifact/javax/javaee-api[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.

[[related-pages]]
Related pages
~~~~~~~~~~~~~

<<IIInjectionAndScopes#ii-injection-and-scopes,"II - Injection and scopes">>