[MYFACES-3617] NullPointerException occurs when using an EL Expression in f:viewParam name attribute

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.15
• Fix Version/s: 2.0.16, 2.1.10
• Component/s: JSR-314
• Environment: WebSphere Application Server 8.0 using MyFaces 2.0.15
• Assignee: Leonardo Uribe
• Reporter: Paul Nicolucci
• Created: 27/Sep/12 18:53
• Updated: 20/Nov/12 23:44
• Resolved: 03/Oct/12 15:54

Description

When using a f:viewParm on a page and using an EL Expression in the name attribute of the f:viewParm the following NullPointerException occurs:

java.lang.NullPointerException
at org.apache.myfaces.util.AbstractAttributeMap.get(AbstractAttributeMap.java:94)
at javax.faces.component.UIViewParameter.decode(UIViewParameter.java:84)
at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1377)
at javax.faces.component.UIInput.processDecodes(UIInput.java:188)
at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1371)
at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1365)
at javax.faces.component.UIViewRoot._processDecodesDefault(UIViewRoot.java:1406)
at javax.faces.component.UIViewRoot.access$400(UIViewRoot.java:74)
at javax.faces.component.UIViewRoot$ApplyRequestValuesPhaseProcessor.process(UIViewRoot.java:1497)
at javax.faces.component.UIViewRoot._process(UIViewRoot.java:1372)
at javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:759)
at org.apache.myfaces.lifecycle.ApplyRequestValuesExecutor.execute(ApplyRequestValuesExecutor.java:38)
at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:171)
at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)

For example the following will work:

<f:viewParam name="firstName" value="#

{userBean.user.firstName}" />

but this would fail:

<f:viewParam name="#{userBean.paramName1}" value="#{userBean.user.firstName}

" />

I'm willing to code up a fix for this issue, but I need a bit of help figuring out where the fix needs to go. It seems the EL expression works fine in the value attribute just not in the name attribute. However according to the JavaDocs name can be an EL Expression.