org.omnifaces.cdi

Annotation Type ViewScoped

@Inherited
@Documented
@NormalScope(passivating=true)
@Retention(value=RUNTIME)
@Target(value={TYPE,METHOD,FIELD})
public @interface ViewScoped

The CDI view scope annotation, intented for use in JSF 2.0/2.1. Just use it the usual way as all other CDI scopes. Watch out with IDE autocomplete on import that you don't accidentally import JSF's own one.

 import javax.inject.Named;
 import org.omnifaces.cdi.ViewScoped;

 @Named
 @ViewScoped
 public class OmniCDIViewScopedBean implements Serializable {}
 

Please note that the bean must implement Serializable, otherwise the CDI implementation will throw an exception about the bean not being passivation capable.

In JSF 2.2, you're supposed to use JSF's own new CDI compatible javax.faces.view.ViewScoped instead; not because this CDI view scope annotation is so bad, in contrary, but just because using the standard solutions should be preferred over alternative solutions if they solve the same problem.

Under the covers, CDI managed beans with this scope are via ViewScopeManager stored in the session scope by an UUID based key which is referenced in JSF's own view map as available by UIViewRoot.getViewMap(). They are not stored in the JSF view map itself as that would be rather expensive in case of client side state saving.

In effects, this CDI view scope annotation has exactly the same lifecycle as JSF's own view scope. One important thing to know and understand is that any PreDestroy annotated method on a CDI view scoped bean isn't immediately invoked in all cases when the view scope ends. This is not specific to CDI, but to JSF itself. For detail, see the following JSF issues related to the matter:

• Mojarra issue 1351
• Mojarra issue 1839
• JSF spec issue 905

Summarized, it's only immediately invoked when the view is either explicitly changed by a non-null/void navigation on a postback, or when the view is explicitly rebuilt by FacesContext.setViewRoot(UIViewRoot). It's not immediately invoked on a GET navigation, nor a close of browser tab/window. This CDI view scope annotation however guarantees that the PreDestroy annotated method is also invoked on session expire, while JSF 2.0/2.1 doesn't do that (JSF 2.2 does).

Configuration

By default, the maximum number of active view scopes is hold in a LRU map with a default size equal to the first non-null value of the following context parameters:

• "org.omnifaces.VIEW_SCOPE_MANAGER_MAX_ACTIVE_VIEW_SCOPES" (OmniFaces)
• "com.sun.faces.numberOfLogicalViews" (Mojarra-specific)
• "org.apache.myfaces.NUMBER_OF_VIEWS_IN_SESSION" (MyFaces-specific)

If none of those context parameters are present, then a default size of 20 will be used. When a view scoped bean is evicted from the LRU map, then its PreDestroy will also guaranteed to be invoked.

Since:

1.6

Author:

Radu Creanga <[email protected]>, Bauke Scholtz

See Also:

ViewScopeExtension, ViewScopeContext, ViewScopeManager, ViewScopeEventListener