...The easy stuff was the ASM dependencies because Errai depends on huice, which uses asm 3 and GWT requires ASM 5.
But this one is strange is java.lang.ClassCastException, which does not stop the app but is irritating. See the attached image.
Anyone see this? Is it GWT 2.7.0 or Errai 3.0.4-SNAPSHOT bug?
I do not see the issue in GWT 2.6.1
The exception seems to be coming from Cast.java:59 in GWT 2.7.0 and is related to my entry point class.
...
static Object dynamicCast(Object src, JavaScriptObject dstId) {
if (src != null && !canCast(src, dstId)) {
throw new ClassCastException();
}
return src;
}
This may actually be a GWT 2.7.0 bug, not Errai:
https://plus.google.com/118379921162257118612/posts/9tp45FJe7QR
Well, better late than never ... finally discovered the source of this nasty exception thanks to this discussion: https://groups.google.com/forum/#!topic/google-web-toolkit/jOlA7S2CwF0
This is still present in Errai 4.1.3-SNAPSHOT and GWT 2.8.2. The issue is that one needs to implement EntryPoint interface in addition to the @EntryPoint annotation like so:
@EntryPoint
public class Main implements com.google.gwt.core.client.EntryPoint{
@Override
public void onModuleLoad() {
//Nothing to do hee since Errai uses CDI for iitialization.
}
}
So why did I get it wrong? Because the Errai tutorial demo sets the this really bad example - see this:
/**
* <p>
* This bean attaches the {@link NavBar} and {@link NavigationPanel} when the application starts.
* <p>
* <p>
* The {@link EntryPoint} scope is like {@link ApplicationScoped} except that entry points are eagerly initilialized
* when the IoC container starts. Consequently, the {@link PostConstruct} of this bean will be invoked when the
* container is initialized.
*/
@EntryPoint
public class AppSetup {
@Inject
private NavigationPanel navPanel;
@Inject
private NavBar navbar;
@Inject
private JQuery $;
@Inject
private HTMLDocument document;
@PostConstruct
public void init() {
RootPanel.get("rootPanel").add(navPanel);
$.wrap($.wrap(document.body).children().first()).before(navbar.getElement());
}
}
So how should this be fixed? Either fix the errai tutorial or make sure the @EntryPoint annotation takes care of implementing the requisite interface.
The issue is that one needs to implement EntryPoint interface in addition to the @EntryPoint annotation like so:
I'm not sure where you're getting this idea from. I've never seen this casting error in Errai Tutorial. The only way I can imagine this would happen is if you made you `@EntryPoint` bean a GWT entrypoint in your *.gwt.xml, but you shouldn't do that.
Thanks Max,
You guessed it right - I did have an entry in the xml module definition, which was causing the issue. If section '1.3.6.3.EntryPoints' is the main place where @EntryPoint is documented, maybe it is a good idea to explicitly warn about this. Also in the examples of sections 2.2.1,2.2.4 the code does implement the EntryPoint interface.