Hi, The error is ‘expected’ as interceptors are dealing with transformed service references and not (genuine) service references. Try to use `transformed.getWrappedReference()` to retrieve the original reference.
Regards, Clement On 3 déc. 2013, at 10:57, Bengt Rodehav <[email protected]> wrote: > I've tried something like this: > > BundleContext bundleContext = > FrameworkUtil.getBundle(IRouteExtender.class).getBundleContext(); > > for (ServiceReference ref : theMatchingRefs) { > IRouteExtender extender = (IRouteExtender) bundleContext.getService(ref); > // Causes exception > System.out.println("Found extender with id: " + extender.getExtenderId()); > } > > But I get the following exception: > > ERROR: Bundle se.digia.connect.services.generic.service [164] > EventDispatcher: Error during dispatch. (java.lang.ClassCastException: > org.apache.felix.ipojo.dependency.impl.TransformedServiceReferenceImpl > cannot be cast to > org.apache.felix.framework.ServiceRegistrationImpl$ServiceReferenceImpl) > java.lang.ClassCastException: > org.apache.felix.ipojo.dependency.impl.TransformedServiceReferenceImpl > cannot be cast to > org.apache.felix.framework.ServiceRegistrationImpl$ServiceReferenceImpl > at > org.apache.felix.framework.ServiceRegistry.getService(ServiceRegistry.java:250) > at org.apache.felix.framework.Felix.getService(Felix.java:3420) > at > org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:468) > at > se.digia.connect.service.generic.service.ExtenderInterceptor.__M_calculateExtenders(ExtenderInterceptor.java:104) > at > se.digia.connect.service.generic.service.ExtenderInterceptor.calculateExtenders(ExtenderInterceptor.java) > at > se.digia.connect.service.generic.service.ExtenderInterceptor.__M_getServiceReferences(ExtenderInterceptor.java:84) > at > se.digia.connect.service.generic.service.ExtenderInterceptor.getServiceReferences(ExtenderInterceptor.java) > at > org.apache.felix.ipojo.dependency.interceptors.DefaultServiceRankingInterceptor.onServiceArrival(DefaultServiceRankingInterceptor.java:61) > at > org.apache.felix.ipojo.dependency.impl.ServiceReferenceManager.applyRankingOnArrival(ServiceReferenceManager.java:559) > at > org.apache.felix.ipojo.dependency.impl.ServiceReferenceManager.onNewMatchingService(ServiceReferenceManager.java:510) > at > org.apache.felix.ipojo.dependency.impl.ServiceReferenceManager.addedService(ServiceReferenceManager.java:496) > at > org.apache.felix.ipojo.util.Tracker$Tracked.trackAdding(Tracker.java:711) > at > org.apache.felix.ipojo.util.Tracker$Tracked.track(Tracker.java:672) > at > org.apache.felix.ipojo.util.Tracker$Tracked.serviceChanged(Tracker.java:633) > at > org.apache.felix.framework.util.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:932) > at > org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:793) > at > org.apache.felix.framework.util.EventDispatcher.fireServiceEvent(EventDispatcher.java:543) > at > org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4260) > at org.apache.felix.framework.Felix.registerService(Felix.java:3275) > at > org.apache.felix.framework.BundleContextImpl.registerService(BundleContextImpl.java:346) > at > org.apache.felix.ipojo.IPojoContext.registerService(IPojoContext.java:395) > at > org.apache.felix.ipojo.handlers.providedservice.ProvidedService.registerService(ProvidedService.java:338) > at > org.apache.felix.ipojo.handlers.providedservice.ProvidedServiceHandler.__M_stateChanged(ProvidedServiceHandler.java:484) > at > org.apache.felix.ipojo.handlers.providedservice.ProvidedServiceHandler.stateChanged(ProvidedServiceHandler.java) > at > org.apache.felix.ipojo.InstanceManager.setState(InstanceManager.java:536) > at > org.apache.felix.ipojo.InstanceManager.start(InstanceManager.java:418) > at > org.apache.felix.ipojo.ComponentFactory.createInstance(ComponentFactory.java:179) > at > org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:319) > at > org.apache.felix.ipojo.IPojoFactory.createComponentInstance(IPojoFactory.java:240) > at > org.apache.felix.ipojo.IPojoFactory.updated(IPojoFactory.java:737) > at > org.apache.felix.ipojo.ConfigurationTracker.registerFactory(ConfigurationTracker.java:100) > at > org.apache.felix.ipojo.IPojoFactory.computeFactoryState(IPojoFactory.java:846) > at > org.apache.felix.ipojo.ComponentFactory.addedService(ComponentFactory.java:400) > at > org.apache.felix.ipojo.util.Tracker$Tracked.trackAdding(Tracker.java:711) > at > org.apache.felix.ipojo.util.Tracker$Tracked.trackInitialServices(Tracker.java:596) > at org.apache.felix.ipojo.util.Tracker.open(Tracker.java:210) > at > org.apache.felix.ipojo.ComponentFactory.starting(ComponentFactory.java:249) > at org.apache.felix.ipojo.IPojoFactory.start(IPojoFactory.java:671) > at > org.apache.felix.ipojo.extender.internal.linker.ManagedType$ExtensionSupport$1.call(ManagedType.java:229) > at > org.apache.felix.ipojo.extender.internal.linker.ManagedType$ExtensionSupport$1.call(ManagedType.java:216) > at > org.apache.felix.ipojo.extender.internal.queue.JobInfoCallable.call(JobInfoCallable.java:114) > at > java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) > at java.util.concurrent.FutureTask.run(FutureTask.java:138) > at > java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) > at java.lang.Thread.run(Thread.java:662) > > Any ideas? > > BTW, the exception is only logged in the console - not in any log files. > > /Bengt > > > > > 2013/12/3 Bengt Rodehav <[email protected]> > >> I've now tested against trunk and I've come a lot further. Another >> question for you... >> >> I need access to my service object in the getServiceReferences() method. >> It is possible if I have the BundleContext. In the accept() method I get >> the BundleContext passed as a parameter but not in the >> getServiceReferences(). Why is that? >> >> How can I access the service object from the ServiceReference in the >> getServiceReferences() method? Perhaps the signature of the >> getServiceReferences() method should be changed to take a BundleContext as >> well? >> >> /Bengt >> >> >> 2013/11/29 Bengt Rodehav <[email protected]> >> >>> Thanks Clement. I'll check out trunk and see how far I'll get. >>> >>> /Bengt >>> >>> >>> 2013/11/29 Clement Escoffier <[email protected]> >>> >>>> Hi, >>>> On 29 nov. 2013, at 16:21, Bengt Rodehav <[email protected]> wrote: >>>> >>>>> Thanks Clement! >>>>> >>>>> I compared our code it turns out I had a type: I had specified the >>>> handler >>>>> to "org.apache.felix.ipojo.properties" instead of >>>>> "org.apache.felix.ipojo:properties".. I had a period instead of a >>>> colon. >>>>> That explains my NPE. >>>> >>>> I probably did a mistake while explaining. The syntax is >>>> namespace:handlername. >>>> >>>>> >>>>> Now I can also retrieve the property. I can also call the getValue() >>>> method >>>>> that returns the value in "toString" format. Can't get the >>>> getObjectValue() >>>>> to work though. Looking forward to the new getCurrentValue() method. >>>> >>>> Unfortunately the getObjectValue only work for immutable properties. >>>> >>>>> >>>>> Is it just the org.apache.felix.ipojo artifact I need to check out and >>>>> build on trunk? >>>> >>>> The following version contains the new method: >>>> >>>> https://repository.apache.org/content/repositories/snapshots/org/apache/felix/org.apache.felix.ipojo/1.11.1-SNAPSHOT/org.apache.felix.ipojo-1.11.1-20131129.182110-3.jar >>>> >>>> Clement >>>> >>>>> >>>>> /Bengt >>>>> >>>>> >>>>> >>>>> >>>>> 2013/11/29 Clement Escoffier <[email protected]> >>>>> >>>>>> Hi, >>>>>> >>>>>> I’ve done some testing: >>>>>> >>>>>> 1) I’m able to retrieve the properties >>>>>> 2) I’m not able to retrieve the value >>>>>> >>>>>> Here is my accept method: >>>>>> >>>>>> @Override >>>>>> public <S> TransformedServiceReference<S> accept(DependencyModel >>>>>> dependency, BundleContext context, TransformedServiceReference<S> >>>> ref) { >>>>>> ConfigurationHandlerDescription h = >>>>>> (ConfigurationHandlerDescription) >>>>>> dependency.getComponentInstance().getInstanceDescription() >>>>>> >>>>>> .getHandlerDescription("org.apache.felix.ipojo:properties"); >>>>>> >>>>>> if (h == null) { >>>>>> return null; >>>>>> } >>>>>> >>>>>> PropertyDescription description = >>>> h.getPropertyByName(“extenders"); >>>>>> if (description == null) { >>>>>> return null; >>>>>> } >>>>>> >>>>>> System.out.println(description.getValue() + " / " + >>>>>> Arrays.toString( >>>>>> (String[]) description.getCurrentValue())); >>>>>> >>>>>> return ref; >>>>>> } >>>>>> >>>>>> I’ve added the getCurrentValue() to PropertyDescription to retrieve >>>> the >>>>>> current property value (gonna commit this ASAP). >>>>>> (full code here: https://gist.github.com/cescoffier/7705901) >>>>>> >>>>>> Clement >>>>>> >>>>>> On 28 nov. 2013, at 15:06, Bengt Rodehav <[email protected]> wrote: >>>>>> >>>>>>> Thanks! >>>>>>> >>>>>>> >>>>>>> 2013/11/28 Clement Escoffier <[email protected]> >>>>>>> >>>>>>>> >>>>>>>> On 28 nov. 2013, at 14:36, Bengt Rodehav <[email protected]> wrote: >>>>>>>> >>>>>>>>> Hello Clement, >>>>>>>>> >>>>>>>>> I changed to the following line: >>>>>>>>> >>>>>>>>> PropertyDescription[] propDescs = >>>>>>>>> configHandlerDescription.getProperties(); >>>>>>>>> >>>>>>>>> But I still get an NPE. Have you tried to call these methods from >>>>>> within >>>>>>>> an >>>>>>>>> interceptor? >>>>>>>> >>>>>>>> Not this method, but I did something pretty similar. Will >>>> investigate to >>>>>>>> see why you get an NPE. >>>>>>>> >>>>>>>> Clement >>>>>>>> >>>>>>>>> >>>>>>>>> /Bengt >>>>>>>>> >>>>>>>>> >>>>>>>>> 2013/11/28 Clement Escoffier <[email protected]> >>>>>>>>> >>>>>>>>>> >>>>>>>>>> On 28 nov. 2013, at 12:17, Bengt Rodehav <[email protected]> >>>> wrote: >>>>>>>>>> >>>>>>>>>>> Hello again Clement! >>>>>>>>>>> >>>>>>>>>>> I was away on business yesterday which is why I'm late replying. >>>>>>>>>>> >>>>>>>>>>> I've come a bit further now but still have problems accessing my >>>>>>>>>>> component's "extenders" property. Here is what my code looks like >>>>>> now: >>>>>>>>>>> >>>>>>>>>>> * public List<ServiceReference> >>>> getServiceReferences(DependencyModel >>>>>>>>>>> theDependencyModel,* >>>>>>>>>>> * List<ServiceReference> theMatching) {* >>>>>>>>>>> >>>>>>>>>>> * ComponentInstance instance = >>>>>>>>>>> theDependencyModel.getComponentInstance();* >>>>>>>>>>> * InstanceDescription instanceDescription = >>>>>>>>>>> instance.getInstanceDescription();* >>>>>>>>>>> * ComponentTypeDescription componentTypeDescription = >>>>>>>>>>> instanceDescription.getComponentDescription();* >>>>>>>>>>> * String factoryName = >>>>>>>>>>> componentTypeDescription.getFactory().getFactoryName();* >>>>>>>>>>> >>>>>>>>>>> * if (FACTORY_NAME.equals(factoryName)) {* >>>>>>>>>>> * System.out.println("Found a GenericService2");* >>>>>>>>>>> * ConfigurationHandlerDescription configHandlerDescription = >>>>>>>>>>> (ConfigurationHandlerDescription) instanceDescription* >>>>>>>>>>> * >>>>>>>> .getHandlerDescription("org.apache.felix.ipojo.properties");* >>>>>>>>>>> * int state = instanceDescription.getState();* >>>>>>>>>>> * System.out.println("State: " + state);* >>>>>>>>>>> * if(ComponentInstance.VALID == >>>> instanceDescription.getState()) >>>>>> {* >>>>>>>>>>> * PropertyDescription propDesc = >>>>>>>>>>> configHandlerDescription.getPropertyByName("extenders"); // NPE* >>>>>>>>>>> * if(propDesc != null) {* >>>>>>>>>>> * String extenders = propDesc.getValue();* >>>>>>>>>>> * System.out.println("Extenders: " + extenders);* >>>>>>>>>>> * }* >>>>>>>>>>> * else {* >>>>>>>>>>> * System.out.println("Extenders is null");* >>>>>>>>>>> * }* >>>>>>>>>>> * }* >>>>>>>>>>> * }* >>>>>>>>>>> >>>>>>>>>>> I check the factory name to determine if this is a component >>>> that I >>>>>>>>>> should >>>>>>>>>>> intercept. Presently I wait until the component is valid but I'm >>>> not >>>>>>>> sure >>>>>>>>>>> if I can wait since my interceptor has to kick in before that. >>>>>>>> Presently >>>>>>>>>> I >>>>>>>>>>> get a null pointer exception when I try to retrieve my property. >>>> Do >>>>>> you >>>>>>>>>>> have any idea why? It doesn't seem possible to retrieve >>>> properties at >>>>>>>>>> this >>>>>>>>>>> pont. >>>>>>>>>> >>>>>>>>>> Did you try to inter ate over the set of properties and see what >>>> are >>>>>>>> they ? >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> I also noticed that the method PropertyDescription.getValue() >>>> always >>>>>>>>>>> returns a String. In my case the underlying object is an array of >>>>>>>> String >>>>>>>>>>> (String[]). Is it possible to get the value in the correct type? >>>>>>>>>> >>>>>>>>>> Yes, there is a getObjectValue(BundleContext context) method, but >>>> you >>>>>>>> need >>>>>>>>>> to give a bundle context object used if it needs to load classes. >>>>>>>>>> >>>>>>>>>> Clement >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> /Bengt >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> 2013/11/27 Clement Escoffier <[email protected]> >>>>>>>>>>> >>>>>>>>>>>> Hi, >>>>>>>>>>>> >>>>>>>>>>>> On 26 nov. 2013, at 16:00, Bengt Rodehav <[email protected]> >>>> wrote: >>>>>>>>>>>> >>>>>>>>>>>>> I'm getting a bit closer regarding the interceptors. Still two >>>>>>>> problems >>>>>>>>>>>> for >>>>>>>>>>>>> me: >>>>>>>>>>>>> >>>>>>>>>>>>> a) I still don't understand how to get hold of my intercepted >>>>>>>> instance >>>>>>>>>>>> from >>>>>>>>>>>>> within my interceptor. I get a reference to a DependencyModel >>>> from >>>>>>>>>> which >>>>>>>>>>>> I >>>>>>>>>>>>> can get a ComponentInstance. But how do I go from there to my >>>>>>>>>> ComponentA >>>>>>>>>>>>> class. I need to access the property "extenders" in order for >>>> my >>>>>>>>>>>>> interceptor to do its job. >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> It depends how how is managed the extender property, let’s >>>> imagine >>>>>>>> it’s >>>>>>>>>> a >>>>>>>>>>>> @Property. In this case, from the Dependency Model, you can >>>> retrieve >>>>>>>> the >>>>>>>>>>>> component instance. From the instance, you have access to the >>>>>>>>>> introspection >>>>>>>>>>>> layer (getInstanceDescription()), which let you analyze the >>>> iPOJO >>>>>>>>>> container. >>>>>>>>>>>> >>>>>>>>>>>> To be a bit more clear, let’s see some code: >>>>>>>>>>>> >>>>>>>>>>>> //First retrieve the configuration handler description from the >>>>>>>> instance >>>>>>>>>>>> container: >>>>>>>>>>>> ConfigurationHandlerDescription description = >>>>>>>>>>>> (ConfigurationHandlerDescription) >>>>>>>>>>>> >>>>>>>>>> >>>>>>>> >>>>>> >>>> model.getComponentInstance().getInstanceDescription().getHandlerDescription("org.apache.felix.ipojo.properties”); >>>>>>>>>>>> // Find the extenders property >>>>>>>>>>>> String extenders = >>>>>>>>>> description.getPropertyByName("extenders").getValue(); >>>>>>>>>>>> // You have your value ! >>>>>>>>>>>> >>>>>>>>>>>>> b) Also, when the property "extenders" is changed, I need to >>>> force >>>>>>>> the >>>>>>>>>>>>> interceptor to recalculate the dependencies. How can I >>>> accomplish >>>>>>>> that? >>>>>>>>>>>> >>>>>>>>>>>> It also depends on how this reconfiguration happen. Let’s say >>>> that >>>>>> the >>>>>>>>>>>> instance is reconfigured from the configuration admin or iPOJO >>>>>>>>>>>> reconfiguration abilities. In these case being notified is quite >>>>>>>>>> simple, as >>>>>>>>>>>> you can register a ConfigurationListener on the >>>>>>>>>>>> ConfigurationHandlerDescription object: >>>>>>>>>>>> >>>>>>>>>>>> description.addListener(new ConfigurationListener() { >>>>>>>>>>>> public void configurationChanged(ComponentInstance >>>>>> instance, >>>>>>>>>>>> Map<String, Object> configuration) { >>>>>>>>>>>> // The extender property may have been modified >>>>>>>>>>>> } >>>>>>>>>>>> }); >>>>>>>>>>>> >>>>>>>>>>>> Don’t forget to unregister the listener when the interceptor is >>>>>>>>>> unplugged >>>>>>>>>>>> from the instance. >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> Getting deeper into iPojo than I've been before… >>>>>>>>>>>> >>>>>>>>>>>> It’s just the beginning…. (contributions are welcome if you see >>>> some >>>>>>>>>>>> dark(er) area) >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> /Bengt >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> 2013/11/26 Bengt Rodehav <[email protected]> >>>>>>>>>>>>> >>>>>>>>>>>>>> Thanks Clement! >>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> 2013/11/26 Clement Escoffier <[email protected]> >>>>>>>>>>>>>> >>>>>>>>>>>>>>> Hi, >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> On 25 nov. 2013, at 20:19, Bengt Rodehav <[email protected]> >>>>>>>> wrote: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Hello Clement and as always thanks for your detailed answer! >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> You’re welcome. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> It does seem a bit complicated to "require" an interceptor. >>>>>>>> Perhaps >>>>>>>>>> an >>>>>>>>>>>>>>>> easier way of doing this might be possible in the future. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> I think it would be a good addition. Thinking about it. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Anyway, I'm not >>>>>>>>>>>>>>>> exactly sure that I understood what you meant. Just to >>>> clarify: >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> My Component A (the component to be intercepted) has the >>>>>> following >>>>>>>>>>>> code: >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> @Property(name = "extenders", mandatory = false) >>>>>>>>>>>>>>>> private String[] mExtenderIds; >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> @Requires(optional = true, id = "extenders") >>>>>>>>>>>>>>>> private IExtender[] mExtenders; >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Do you mean that I should put a filter on the @Requires with >>>>>>>>>>>>>>> id="extenders" >>>>>>>>>>>>>>>> (the intercepted = true) so that it can only be satisfied >>>> if my >>>>>>>>>>>>>>> interceptor >>>>>>>>>>>>>>>> has added that property? >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Exactly. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> But how do I then handle the situation where my Component A >>>> does >>>>>>>> not >>>>>>>>>>>>>>>> require any extenders? In that case I was planning on >>>> setting >>>>>> the >>>>>>>>>>>>>>>> dependency to optional to make my instance valid without any >>>>>>>>>>>> extenders. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Or, perhaps I could first set the @Requires to mandatory >>>> (with >>>>>> the >>>>>>>>>>>>>>> filter): >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> @Requires(optional = false, id = "extenders", >>>>>>>>>>>>>>> filter="(intercepted=true)") >>>>>>>>>>>>>>>> private IExtender[] mExtenders; >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Then, if my interceptor sees that the instance does not >>>> require >>>>>>>> any >>>>>>>>>>>>>>>> extenders it can set the dependency to become optional. This >>>>>> way I >>>>>>>>>>>> both >>>>>>>>>>>>>>>> require the interceptor (via the filter) and I ensure that >>>> the >>>>>>>> only >>>>>>>>>>>> way >>>>>>>>>>>>>>> to >>>>>>>>>>>>>>>> allow the instance to be valid without the dependency is if >>>> the >>>>>>>>>>>>>>> interceptor >>>>>>>>>>>>>>>> has explicitly set the dependency to optional. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> That would work. You can change the optionality status of the >>>>>>>>>>>> dependency >>>>>>>>>>>>>>> from the dependency model you get in the interceptor. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Regards, >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Clement >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> /Bengt >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> 2013/11/25 Clement Escoffier <[email protected]> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Hi, >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> On 25 nov. 2013, at 11:04, Bengt Rodehav < >>>> [email protected]> >>>>>>>>>> wrote: >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I've started to investigate using iPojo interceptors. I'm >>>>>> using >>>>>>>>>>>> iPojo >>>>>>>>>>>>>>>>>> version 1.11.0. I want to accomplish the following: >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Component A can be "extended" by specifying a list of >>>>>> (required) >>>>>>>>>>>>>>>>>> "extenders" (actually their id's), like this: >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> @Property(name = "extenders", mandatory = false) >>>>>>>>>>>>>>>>>> private String[] mExtenderIds; >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> @Requires(optional = true, id = "extenders") >>>>>>>>>>>>>>>>>> private IExtender[] mExtenders; >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> The property is optional but if any extenderId's are >>>> listed >>>>>> then >>>>>>>>>> the >>>>>>>>>>>>>>>>>> @Requires should require that IExtender's with the >>>>>> corresponding >>>>>>>>>>>>>>>>> extenderId >>>>>>>>>>>>>>>>>> is started. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> The IExtender interface contains the following method: >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> public String getExtenderId(); >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Thus, every extender has an extenderId and if that id is >>>>>> listed >>>>>>>>>> in a >>>>>>>>>>>>>>>>>> components "extender" property then the corresponding >>>> service >>>>>>>>>> should >>>>>>>>>>>>>>> be >>>>>>>>>>>>>>>>>> required, otherwise not. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> My idea (actually Clement's idea from a previous >>>> conversation >>>>>> on >>>>>>>>>>>> this >>>>>>>>>>>>>>>>>> list). is to use a RankingInterceptor that returns an >>>> empty >>>>>>>> array >>>>>>>>>>>>>>> until >>>>>>>>>>>>>>>>> all >>>>>>>>>>>>>>>>>> required services are present. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I think this is doable but in order for my >>>> RankingInterceptor >>>>>> to >>>>>>>>>>>>>>> work, it >>>>>>>>>>>>>>>>>> must have access to the component's "extenders" property. >>>> It >>>>>>>> would >>>>>>>>>>>>>>> then >>>>>>>>>>>>>>>>> go >>>>>>>>>>>>>>>>>> through all the services implementing the IExtender >>>> interface >>>>>>>> and >>>>>>>>>> if >>>>>>>>>>>>>>>>> there >>>>>>>>>>>>>>>>>> are extenders corresponding to the required extenderId's >>>> it >>>>>>>> would >>>>>>>>>>>>>>> return >>>>>>>>>>>>>>>>>> all of those, otherwise it would return an empty list. >>>> Also, >>>>>> if >>>>>>>> a >>>>>>>>>>>>>>> list of >>>>>>>>>>>>>>>>>> extenderId's was specified, then the service dependency >>>> is set >>>>>>>> to >>>>>>>>>>>>>>>>>> mandatory, otherwise to optional. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> My problem is how to gain access to the configuration >>>> property >>>>>>>>>> (the >>>>>>>>>>>>>>>>>> "extenders" property) of my component from the >>>> interceptor. >>>>>> How >>>>>>>>>> can >>>>>>>>>>>> I >>>>>>>>>>>>>>> do >>>>>>>>>>>>>>>>>> this? >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> When the interceptor is hooked to a dependency, it >>>> receives the >>>>>>>>>>>>>>> dependency >>>>>>>>>>>>>>>>> model object. From this object you can retrieve the >>>> component >>>>>>>>>>>> instance >>>>>>>>>>>>>>> and >>>>>>>>>>>>>>>>> get the introspection metadata. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Another question I have is how to make sure that the >>>>>> interceptor >>>>>>>>>> is >>>>>>>>>>>>>>>>> active. >>>>>>>>>>>>>>>>>> If the interceptor is not active then my component could >>>>>> become >>>>>>>>>>>>>>>>> erroneously >>>>>>>>>>>>>>>>>> valid. Would it be feasible to have a mandatory >>>> dependency on >>>>>>>> the >>>>>>>>>>>>>>>>>> interceptor? >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Unfortunately not, at least not easily. What you can do is >>>> a >>>>>>>>>>>>>>> combination >>>>>>>>>>>>>>>>> between a filter and two interceptors: the ranking >>>> interceptors >>>>>>>> as >>>>>>>>>>>> you >>>>>>>>>>>>>>> did, >>>>>>>>>>>>>>>>> and a tracking interceptor. Let me explain: >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Let’s imagine your consumer with your service dependency. >>>> Add a >>>>>>>>>>>> filter >>>>>>>>>>>>>>>>> that will be resolved only if your interceptor is there, >>>>>>>> something >>>>>>>>>>>>>>> like: >>>>>>>>>>>>>>>>> (intercepted=true). >>>>>>>>>>>>>>>>> Your interceptor implement both tracking and ranking >>>>>>>> interceptors. >>>>>>>>>>>> When >>>>>>>>>>>>>>>>> the accept method is called on your interceptor, it can >>>>>>>>>> ‘transform’ >>>>>>>>>>>>>>> the >>>>>>>>>>>>>>>>> original service reference to add the ‘intercepted’ >>>> property >>>>>>>>>>>>>>>>> (ref.addProperty(“intercepted”, true);) This modified >>>> service >>>>>>>>>>>> reference >>>>>>>>>>>>>>>>> matches your filter. Then, do your ranking policy are we >>>>>>>> discussed. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> This solution ensure that your dependency can only be >>>> resolved >>>>>> if >>>>>>>>>>>> your >>>>>>>>>>>>>>>>> interceptor is there. Indeed without the interceptor, the >>>>>> filter >>>>>>>>>> does >>>>>>>>>>>>>>> not >>>>>>>>>>>>>>>>> match. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Regards, >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Clement >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> /Bengt >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> >>>>>>>>>> >>>> --------------------------------------------------------------------- >>>>>>>>>>>>>>>>> To unsubscribe, e-mail: [email protected] >>>>>>>>>>>>>>>>> For additional commands, e-mail: >>>> [email protected] >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>> >>>> --------------------------------------------------------------------- >>>>>>>>>>>>>>> To unsubscribe, e-mail: [email protected] >>>>>>>>>>>>>>> For additional commands, e-mail: [email protected] >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>> --------------------------------------------------------------------- >>>>>>>>>>>> To unsubscribe, e-mail: [email protected] >>>>>>>>>>>> For additional commands, e-mail: [email protected] >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>> --------------------------------------------------------------------- >>>>>>>>>> To unsubscribe, e-mail: [email protected] >>>>>>>>>> For additional commands, e-mail: [email protected] >>>>>>>>>> >>>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>> --------------------------------------------------------------------- >>>>>>>> To unsubscribe, e-mail: [email protected] >>>>>>>> For additional commands, e-mail: [email protected] >>>>>>>> >>>>>>>> >>>>>> >>>>>> >>>> >>>> >>>> --------------------------------------------------------------------- >>>> To unsubscribe, e-mail: [email protected] >>>> For additional commands, e-mail: [email protected] >>>> >>>> >>> >> --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
