Details
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Bug
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Status: Closed
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Major
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Resolution: Not A Problem
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2.2.12, 2.3.0-beta
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None
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None
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None
Description
When we register an ActionListener or PhaseListener globally via faces-config.xml, the instance that is created per listener is injectable, that is, we can do @Inject in the instance. These listeners are added to the injected bean storage list in the application map and as a result, we can call @PreDestroy and @PostConstruct on this scenario.
On the other hand, when facelet elements <f:actionListener/> and <f:phaseListener/> are used, the instances that are created (per click for action listener or per view for phase listener) are not injectable. That is, we cannot do @Inject inside of these objects. And @PreDestroy and @PostConstruct are not invoked on them.
I supposes we want to have the same behavior in both cases.
To solve this issue, we can probably do a similar logic as what was done in FacesConfigurator that we call inject on the instance, and then store that in the injected bean storage list. We can add that logic in the ActionListenerHandler and PhaseListenerHandler classes after the instance is created.
// Code snippet
instance = (ActionListener) ReflectionUtil.forName(this.type).newInstance();
ExternalContext externalContext = faces.getExternalContext();
// Note that we have to make INJECTED_BEAN_STORAGE_KEY public
List<BeanEntry> injectedBeanStorage = (List<BeanEntry>)externalContext.getApplicationMap().get(FacesConfigurator.INJECTED_BEAN_STORAGE_KEY);
InjectionProvider injectionProvider = InjectionProviderFactory.getInjectionProviderFactory(
externalContext).getInjectionProvider(externalContext);
Object creationMetaData = injectionProvider.inject(instance);
injectedBeanStorage.add(new BeanEntry(instance, creationMetaData));
injectionProvider.postConstruct(instance, creationMetaData);
But there is an issue when adding that. Every time we use <f:actionListener/> with type defined but no binding, a new instance is created on every button click, the same will happen with <f:phaseListener/>. These instances are added to the list of injected bean storage, and that reference will exist until app shuts down, creating a memory leak. So we need a way to remove those references from the list once we are out of scope. We might need a different list for this case.