@ExposedEntity became @Portable ( org.jboss.errai.common.client.api.annotations.Portable ). See Chapter 5, Marshalling for details.

The @Conversational annotation must now target the event objects themselves, not the observer methods of the events. So an event type is either conversational or not; you no longer specify that listeners receive arbitrary events in a conversational context. See the Conversational Events section of the CDI chapter for details.

Errai CDI projects must now use the SimpleDispatcher instead of the AsynDispatcher . This has to be configured in Section 14.2, “Messaging (Errai Bus) Configuration” .

The bootstrap listener (configured in WEB-INF/web.xml ) for Errai CDI has changed ( org.jboss.errai.container.DevModeCDIBootstrap is now org.jboss.errai.container.CDIServletStateListener ).

gwt 2.3.0 or newer must be used and replace older versions.

mvel2 2.1.Beta8 or newer must be used and replace older versions.

weld 1.1.5.Final or newer must be used and replace older versions.

slf4j 1.6.1 or newer must be used and replace older versions.

This step can be skipped if Maven is used to build the project. If the project is NOT built using Maven, the following jar files have to be added manually to project's build/class path: errai-common-2.x.jar, errai-marshalling-2.x.jar, errai-codegen-2.x.jar, netty-4.0.0.Alpha1.errai.r1.jar.

If the project was built using an early version of an Errai archetype the configuration of the maven-gwt-plugin has to be modified to contain the <hostedWebapp>path-to-your-standard-webapp-folder</hostedWebapp> . This is usually either war or src/main/webapp .

Starting with 2.0.CR1 the default for automatic service discovery has been changed in favour of CDI based applications. That means it has to be explicitly turned on for plain bus applications (Errai applications that do not use Errai-CDI). Not doing so will result in NoSubscribersToDeliverTo exceptions. The snippet below shows how to activate automatic service discovery:

<servlet>

  <servlet-name>ErraiServlet</servlet-name>

  <servlet-class>org.jboss.errai.bus.server.servlet.DefaultBlockingServlet</servlet-class>

  <init-param>

    <param-name>auto-discover-services</param-name>

    <param-value>true</param-value>

  </init-param>

  <load-on-startup>1</load-on-startup>

</servlet>

The jboss7-support module was deleted and is no longer needed as a dependency.

Starting with Errai 2.3.0, GWT 2.5.0 or higher is required.

Use your IDE to organize imports at the top level. In eclipse, you'd click in the Project Explorer, press Ctrl-A (select all) and then Ctrl-O (Organize Imports). Other IDEs have similar features.

The ErrorCallback interface has been made more general so the same type can be shared between Errai modules. This allows you reuse your own generic error handler class for, eg, Errai JAX-RS and ErraiBus callbacks. If you want to use a generic error handler throughout your app, change your ErrorCallback implementations to ErrorCallback<?> and change the first argument type of your error() method to Object. Otherwise, if you have use-case-specific error callbacks, implement the interfaces RestErrorCallback or BusErrorCallback as appropriate.

IOCBeanManager was replaced by two new types SyncBeanManager and AsyncBeanManager that need to be used instead. See Section 3.5, “Client-Side Bean Manager” for details.