topic Re: Activiti CDI module and Alternatives in Alfresco Archive

Activiti CDI module and Alternatives

ronnybr — Wed, 30 Jan 2013 10:38:47 GMT

Hello Activiti-Community,I am using CDI in my application quite excessive and I am trying to write my JUnit-tests in a way, that most of my "real" CDI-Beans will be replaced by mocks.Also, I am using Arquillian, so that the injection works.The beans.xml for my tests looks like this:<beans xmlns="

Re: Activiti CDI module and Alternatives

frederikherema1 — Wed, 30 Jan 2013 12:13:29 GMT

I'm not really sure what the behavior should be, when multiple beans are found for the given class-name OR bean-name. I guess it's okay for lookup based on class to ignore "duplicate" entries. But the lookup by name should indeed throw an exception, informing that multiple beans with the same name have been found.

I wonder how the "usual" way of looking up a CDI-bean handles the resolving of what alternatives to return, but I presume the order of the beans returned by the BeanManager reflect the way CDI itself resolves references to beans. Perhaps there is a better way than using the BeanManager to resolve beans, that actually takes into account the "alternatives".

Could you create an issue for this in Jira? Since you're a CDI-expert, can you perhaps add your recommendations on the way beans can be resolved, not using BeanManager? For now, you should override the CDIExpresionManager/CDI-ELResolver until this issue is cleared up…?

Re: Activiti CDI module and Alternatives

ronnybr — Wed, 30 Jan 2013 13:53:39 GMT

Thank you Frederik for your fast answer.
I'll create the JIRA issue later today and think about a possible (and elegant) solution.

Ususally, when CDI resolves alternatives for beans, activated alternatives always beat the normal class. And two possible, activated alternatives will result in an exception during deployment.

So far I solved the problem for me without changing Activiti-code. I am using delegates. The class, the BPMN-XML references, is now mostly empty, e.g.


@Named("praxisberichtVeroeffentlichen")
@Dependent
public class PraxisberichtVeroeffentlichen {

 @Inject
 private PraxisberichtVeroeffentlichenDelegate delegate;

 public void veroeffentlichen(String student, String thema) {
  delegate.veroeffentlichen(student, thema);
 }
}

and the delegate is being replaced by a mock durung JUnit-tests.
The delegate does all the work now.

Re: Activiti CDI module and Alternatives

frederikherema1 — Wed, 30 Jan 2013 13:55:50 GMT

I see, so you're currently relying on CDI to injecting the alternative inside en in-the-middle-bean, resolved by Activiti, to overcome this issue?

Re: Activiti CDI module and Alternatives

ronnybr — Wed, 30 Jan 2013 14:00:19 GMT

Exactly. Activiti's CDIResolver get's one bean from the ProgrammaticBeanLookup and that bean has been initialized by CDI. That way, the alternative is taken, when running the JUnit-tests.

At least, that's how I understand all this CDI magic

Re: Activiti CDI module and Alternatives

ronald_van_kuij — Wed, 30 Jan 2013 20:31:56 GMT

Exactly. Activiti's CDIResolver get's one bean from the ProgrammaticBeanLookup and that bean has been initialized by CDI. That way, the alternative is taken, when running the JUnit-tests.

At least, that's how I understand all this CDI magic

It is an option… An other option might be to have the resolver look at the @Alternative annotation and use that one instead of the normal bean. That requires a change to the code though… Not even sure it works….

Re: Activiti CDI module and Alternatives

ronnybr — Thu, 31 Jan 2013 06:06:32 GMT

An other option might be to have the resolver look at the @Alternative annotation…

For me, it doesn't seem right to try to implement something the CDI framework should already be able to provide, like privilige alternatives.

The resolve() method from BeanManager looks like a good solution.
http://www.grepcode.com/file/repo1.maven.org/maven2/javax.enterprise/cdi-api/1.0/javax/enterprise/inject/spi/BeanManager.java#BeanManager.resolve%28java.util.Set%29

I changed some code in the ProgrammaticBeanLookup and had a short JUnit test check whether it works or not. And it seems to do what the signature promises
But I didn't have much time yesterday so I couldn't test it thoroughly.

Re: Activiti CDI module and Alternatives

frederikherema1 — Thu, 31 Jan 2013 09:37:48 GMT

I'll have a deeper look into the resolve() alternative, see https://jira.codehaus.org/browse/ACT-1557