hi pieter, since it's quite different from the classical approach and it depends on the concrete usage, i would suggest that we talk about it in our irc channel (afterwards we post the solution).
regards, gerhard http://www.irian.at Your JSF powerhouse - JSF Consulting, Development and Courses in English and German Professional Support for Apache MyFaces 2011/8/3 Gerhard Petracek <[email protected]> > hi pieter, > > ok - in this case that won't work (that's a logical cycle). > i thought more about a producer which creates a dependent scoped > transaction. however, as i see that won't help you in this special case. > imo something like a lazy transaction should work. i'll think about it and > create a demo. > > regards, > gerhard > > http://www.irian.at > > Your JSF powerhouse - > JSF Consulting, Development and > Courses in English and German > > Professional Support for Apache MyFaces > > > > 2011/8/3 Pieter Martin <[email protected]> > >> Hi, >> >> The code below does have a producer for the transaction. But it threw an >> exception. >> I changed the code slightly now but am still getting the same exception. >> >> >> public class ConversationListener { >> >> @ApplicationScopedDb >> @Inject >> NakedGraph db; >> >> @ConversationScoped >> @Produces >> public Transaction getTransaction() { >> db.setTransactionMode(Mode.**MANUAL); >> db.startTransaction(); >> return db.getTransaction(); >> } >> >> public void onStartConversation(@Observes StartConversationEvent event, >> Transaction t) { >> System.out.println(t); >> >> } >> >> public void onCloseConversation(@Observes CloseConversationEvent event) >> { >> db.stopTransaction(Conclusion.**SUCCESS); >> } >> >> } >> >> The StartConversationEvent is fired but the transaction parameter can not >> be resolved. Getting the following exception >> >> >> Caused by: java.lang.NullPointerException >> at org.apache.myfaces.extensions.**cdi.core.impl.scope.**conversation. >> **ConversationContextAdapter.**get(**ConversationContextAdapter.** >> java:100) >> at org.apache.webbeans.context.**CustomContextImpl.get(** >> CustomContextImpl.java:48) >> at org.apache.webbeans.context.**CustomPassivatingContextImpl.**get(** >> CustomPassivatingContextImpl.**java:47) >> at org.apache.webbeans.intercept.**NormalScopedBeanInterceptorHan** >> dler.getContextualInstance(**NormalScopedBeanInterceptorHan** >> dler.java:127) >> at org.apache.webbeans.intercept.**NormalScopedBeanInterceptorHan** >> dler.invoke(**NormalScopedBeanInterceptorHan**dler.java:95) >> at org.javassist.tmp.java.lang.**Object_$$_javassist_26.** >> toString(Object_$$_javassist_**26.java) >> at java.lang.String.valueOf(**String.java:2838) >> at java.io.PrintStream.println(**PrintStream.java:788) >> at org.nakeduml.environment.**ConversationListener.** >> onStartConversation(**ConversationListener.java:38) >> >> Not sure why the producer method can not be called. Is the producer method >> incorrect, does it need a qualifier? >> >> Thanks >> Pieter >> >> >> On 02/08/2011 21:19, Gerhard Petracek wrote: >> >>> hi pieter, >>> >>> the concept of outjection is deprecated. >>> >>> you could create a producer method for the transaction. >>> if you need the transaction in an observer, you just have to add it as >>> additional parameter and the produced transaction will be injected into >>> the >>> observer method by cdi. >>> >>> regards, >>> gerhard >>> >>> http://www.irian.at >>> >>> Your JSF powerhouse - >>> JSF Consulting, Development and >>> Courses in English and German >>> >>> Professional Support for Apache MyFaces >>> >>> >>> >>> >>> 2011/8/2 Pieter Martin<[email protected]**> >>> >>> Hi, >>>> >>>> I have the following requirement / problem. >>>> >>>> I would like to implement a long running transaction that is in sync >>>> with a >>>> conversation. I.e. I want to start a transaction when the conversation >>>> starts and commit the transaction when the conversation ends. >>>> >>>> So the transaction will be suspended and resumed in between requests. >>>> >>>> So far I am able to observe the StartConversationEvent and start a >>>> transaction. But I do not know how then to make sure that the >>>> transaction >>>> will be available in the conversation context. >>>> >>>> The code is as follows. >>>> >>>> @RequestScoped >>>> public class ConversationListener { >>>> >>>> @ApplicationScopedDb >>>> @Inject >>>> NakedGraph db; >>>> Transaction transaction; >>>> >>>> @ConversationScoped >>>> @Produces >>>> public Transaction getTransaction() { >>>> return this.transaction; >>>> } >>>> >>>> public void onStartConversation(@Observes StartConversationEvent >>>> event) >>>> { >>>> db.startTransaction(); >>>> transaction = db.getTransaction(); >>>> // Force producer to be called, to plonk the transaction in the >>>> // conversation >>>> // Like seam 2 outjection >>>> Transaction t = getInstance(Transaction.class)****; >>>> //This throws a NullPointerException >>>> t.toString(); >>>> } >>>> >>>> public void onCloseConversation(@Observes CloseConversationEvent >>>> event) >>>> { >>>> //The faces listener would have made sure the correct transaction >>>> is >>>> associated with this thread >>>> db.stopTransaction(Conclusion.****SUCCESS); >>>> } >>>> >>>> public<T> T getInstance(Class<T> type, Annotation... qualifiers) { >>>> BeanManager beanManager = getBeanManager(); >>>> Bean<T> bean = (Bean<T>) beanManager.resolve(**** >>>> beanManager.getBeans(type, >>>> qualifiers)); >>>> CreationalContext<?> ctx = beanManager.** >>>> createCreationalContext(bean); >>>> return (T) beanManager.getReference(bean, type, ctx); >>>> } >>>> >>>> private BeanManager getBeanManager() { >>>> return BeanManagerProvider.****getInstance().getBeanManager()** >>>> **; >>>> } >>>> >>>> } >>>> >>>> The above code does not work, it throws the following exception >>>> >>>> Caused by: java.lang.NullPointerException >>>> at org.apache.myfaces.extensions.****cdi.core.impl.scope.**** >>>> conversation.* >>>> *ConversationContextAdapter.****get(****ConversationContextAdapter.**** >>>> java:100) >>>> at org.apache.webbeans.context.****CustomContextImpl.get(** >>>> CustomContextImpl.java:48) >>>> at org.apache.webbeans.context.****CustomPassivatingContextImpl.*** >>>> *get(** >>>> CustomPassivatingContextImpl.****java:47) >>>> at org.apache.webbeans.intercept.****** >>>> NormalScopedBeanInterceptorHan**** >>>> dler.getContextualInstance(****NormalScopedBeanInterceptorHan**** >>>> dler.java:127) >>>> at org.apache.webbeans.intercept.****** >>>> NormalScopedBeanInterceptorHan**** >>>> dler.invoke(****NormalScopedBeanInterceptorHan****dler.java:95) >>>> >>>> at org.javassist.tmp.java.lang.****Object_$$_javassist_26.** >>>> toString(Object_$$_javassist_****26.java) >>>> >>>> If this were to work the idea is then to suspend and resume the code in >>>> faces listeners >>>> >>>> @RequestScoped >>>> public class FacesListener { >>>> @ApplicationScopedDb >>>> @Inject >>>> NakedGraph db; >>>> @Inject >>>> Logger logger; >>>> >>>> public void beforeFacesRequest(@Observes @BeforeFacesRequest >>>> FacesContext ctx) { >>>> logger.fine("****beforeFacesRequest, setting db on thread"); >>>> GraphDb.setDb(db); >>>> //Need to check here somehow if a conversation has been started >>>> or >>>> not. >>>> Transaction t = CdiEnvironment.getInstance().**** >>>> getComponent(Transaction.****class); >>>> db.resume(t); >>>> } >>>> >>>> public void afterFacesRequest(@Observes @AfterFacesRequest >>>> FacesContext >>>> ctx) { >>>> logger.fine("****afterFacesRequest, suspend transaction and >>>> removing >>>> db from thread"); >>>> Transaction t = db.suspend(); >>>> //Do not need to anything with this transaction as it is already >>>> in >>>> the conversation context >>>> GraphDb.remove(); >>>> } >>>> >>>> } >>>> >>>> Hope it makes sense. >>>> Is there a (better) way to do this? >>>> >>>> Thanks >>>> Pieter >>>> >>>> >>>> >>>> >>>> >> >
