Hi, Thanks for the reply. I added more details to my question.
(message bellow) On Sun, Aug 9, 2009 at 11:49 AM, Vincent Massol <[email protected]> wrote: > Hi Anamaria, > > On Aug 9, 2009, at 2:39 AM, Anamaria Stoica wrote: > > > Hi, > > > > In order to integrate Shindig with the XWiki datastore, 4 interfaces > > have to > > be implemented: PersonService, AppDataService, ActivityService and > > MessagesService (javadocs here [0]). To this end, I have created the > > xwiki-social-opensocial module [1]. > > > > While implementing PersonService (PersonServiceXW - [2]), I have > > encountered > > the following problem: > > As I needed to access the datastore, I also made PersonServiceXW a > > XWiki > > Component in order to gain access to the DocumentAccessBridge > > Component. > > BUT, here is the problem, the DocumentAccessBridge never gets > > initialized > > and at runtime is null. > > > > The reason this might happen, as Sergiu suggested, is that Shindig > > uses > > Guice to bind the services implementations in its code, thus the > > PersonServiceXW component never gets to be registered with XWiki's > > Component > > Manager. > > There's no magic. If the component is registered in components.txt and > if you're looking it up to access it the DAB will get set properly. > So it's just that you're no looking it up and there's no way it can be > injected with dependencies. The component is registered in components.txt, see https://svn.xwiki.org/svnroot/xwiki/sandbox/gsoc/opensocial/xwiki-social-opensocial/src/main/resources/META-INF/components.txt. I'm not sure how I am supposed to look my component up, I mean where. I do look up DAB from my component, but not my component from another place. > > My question is how do I get data in and out XWiki's datastore from the > > PersonService implementation, if I cannot use the > > DocumentAccessBridge this > > way? > > Why couldn't you use it? I did manage to use it with the @Requirement annotation, but as I said, it's null. > > > > Can it be registered to the Component Manager somehow, or is there a > > completely different way this could be achieved? > > You're not provided enough information so that we can help you. > > From what I read the solution is extra simple: just look up the > component using XWiki's component manager and you're done. > OK, I tried this with the following code: EmbeddableComponentManager ecm = new EmbeddableComponentManager(); ecm.initialize(this.getClass().getClassLoader()); documentAccessBridge = ecm.lookup(DocumentAccessBridge.class); if (!documentAccessBridge.exists("XWiki.Julia")) { do smth } But I get a NPE when trying to get the context from DefaultExtension: java.lang.NullPointerException at org.xwiki.context.internal.DefaultExecution.getContext(DefaultExecution.java:67) at com.xpn.xwiki.doc.DefaultDocumentAccessBridge.getContext(DefaultDocumentAccessBridge.java:58) at com.xpn.xwiki.doc.DefaultDocumentAccessBridge.exists(DefaultDocumentAccessBridge.java:148) (see full stacktrace here http://ana-s-private-labs.pastebin.com/m655cdf70) > > Now the only question is what shinding requires. Does it accept an > instance of PersonService or does it take a class. In other words does > it perform the instantiation itself (the new) or can you pass to it an > already instantiated object? It looks like you can bind an instance to type in Guice. This is done either with Instance Bindings, @Provides Methods or Provider Bindings, depending on the complexity of the class. (http://code.google.com/p/google-guice/wiki/Bindings) All bindings are defined in a class that extends AbstractModule, this would be XWSocialModule in my code ( https://svn.xwiki.org/svnroot/xwiki/sandbox/gsoc/opensocial/xwiki-social-opensocial/src/main/java/org/xwiki/opensocial/social/XWSocialModule.java). These modules are then passed as arguments to Guice.createInjector(), which builds the injector. In my application, the injector is build by GuiceServletContextListener ( http://svn.apache.org/repos/asf/incubator/shindig/trunk/java/common/src/main/java/org/apache/shindig/common/servlet/GuiceServletContextListener.java) This servlet takes the context parameters defined in my web.xml; these are: <context-param> <param-name>guice-modules</param-name> <param-value> org.apache.shindig.common.PropertiesModule: org.apache.shindig.gadgets.DefaultGuiceModule: org.apache.shindig.gadgets.oauth.OAuthModule: org.apache.shindig.common.cache.ehcache.EhCacheModule: org.xwiki.opensocial.social.XWSocialModule </param-value> </context-param> <listener> <listener-class>org.xwiki.container.servlet.XWikiServletContextListener</listener-class> </listener> Now, all I need to do is bind the instance of PersonServiceXW after it has been initialized by XWiki's Component Manager. The binding will be done in XWSocialModule, using one of the instance binding methods (Instance Bindings, @Provides Methods or Provider Bindings). My questions are: 1. How do I make sure PersonServiceXW has been initialized already by the XWiki CM before binding it for Guice ? 2. How do I get the initialized PersonServiceXW instance from XWSocialModule ? > *IF* (and if) it controls the instantiation then you need to do it > differently: > - knowing guice you can configure if to inject an instance instead of > a class so that might be a direction to look into > - otherwise simply make you person service impl a standard POJO and > have a setDAB method that you call after it's been instantiated by > shindig somehow. > > [snip] > > Thanks > -Vincent > > _______________________________________________ > devs mailing list > [email protected] > http://lists.xwiki.org/mailman/listinfo/devs > Thanks a lot, Anamaria _______________________________________________ devs mailing list [email protected] http://lists.xwiki.org/mailman/listinfo/devs
