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I am trying to inject JSF ViewScoped bean as ManagedProperty into a RequestScoped bean which implements javax.faces.validator.Validator. But always a fresh copy of ViewScoped bean is injected.
ViewScoped Bean
@ViewScoped
@ManagedBean
public class Bean {
private Integer count = 1;
private String field2;
public String action(){
++count;
return null;
}
public String anotherAction(){
return null;
}
//getter and setter
}
Validator
@RequestScoped
@ManagedBean
public class SomeValidator implements Validator {
public void validate(FacesContext context, UIComponent comp, Object value)
throws ValidatorException {
//logging bean.getCount() is always one here. Even after calling ajax action a few times
}
@ManagedProperty(value = "#{bean}")
private Bean bean;
}
xhtml page
<!DOCTYPE html>
<html lang="en" xmlns="http://www.w3.org/1999/xhtml" xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
</h:head>
<h:body>
<h:form>
<h:panelGroup layout="block" id="panel1">
<h:commandButton type="submit" value="Action" action="#{bean.action}">
<f:ajax render="panel1"></f:ajax>
</h:commandButton>
<h:outputText value="#{bean.count}"></h:outputText>
</h:panelGroup>
<h:panelGroup layout="block" id="panel2">
<h:inputText type="text" value="#{bean.field1}">
<f:validator binding="#{someValidator}" />
</h:inputText>
</h:panelGroup>
<h:commandButton type="submit" value="Another Action" action="#{bean.anotherAction}">
<f:ajax execute="panel2" render="panel2"></f:ajax>
</h:commandButton>
</h:form>
</h:body>
</html>
As mentioned in code, even after calling ajax action a few times, when logging bean.getCount() always display one.
But the same scenario works if I change ViewScoped to SessionScoped. Also if I remove Validator implementation of RequestScoped bean and use a logger in PostConstruct, the count does increment for every ajax request as expected.
Am I doing something wrong? or is this how it should work? Thanks in advance
772
That's because binding attribute of <f:validator> is evaluated during view build time. At that moment, the view scope is not available yet (it makes sense, it's still busy being built...), so a brand new view scoped bean would be created which has then the same effect as a request scoped bean. In the upcoming JSF 2.2, this chicken-egg issue will be solved.
Until then, if you're absolutely positive that you need a view scoped bean inside the validate() method (I'd rather look for other ways such as <f:attribute>, EJBs, multi-field validators, etc), then the only way would be evaluating #{bean} programmatically inside validate() method itself instead of getting it injected by @ManagedProperty.
You can use Application#evaluateExpressionGet() for this:
Bean bean = context.getApplication().evaluateExpressionGet(context, "#{bean}", Bean.class);
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