EL 3.0 static field resolution does not work

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• <h:outputText value="# {Boolean.TRUE}

  " /> prints out nothing.

• It's expected to print out "true"

Environment

WildFly 8.1.Final, which include EL 3.0

Affected Versions

[2.2.7]

[ren-zhijun-oracle]

@javaserverfaces Commented
Reported by hugh_nguyen_82

[ren-zhijun-oracle]

@javaserverfaces Commented
hugh_nguyen_82 said:
Fix proposal:

• Make ScopedAttributeELResolver to resolve the class name (e.g. Boolean) by adding the following code in getValue(), after // check application section

// check static class
if (context.getImportHandler() != null) {
final Class<?> c = context.getImportHandler().resolveClass(attribute);
if (c != null)

{ return new ELClass(c); }

}

• Make DemuxCompositeELResolver to use the correct resolver chain that contain StaticFieldELResolver when resolving property with base being an ELClass object, by replacing a check in getValue(), from

if (base == null) {
to

if (base == null || base instanceof ELClass) {

[ren-zhijun-oracle]

@javaserverfaces Commented
@manfredriem said:
Closing this as a duplicate of https://java.net/jira/browse/GLASSFISH-20778

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@javaserverfaces Commented
Marked as duplicate on Wednesday, August 6th 2014, 2:42:39 pm

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@javaserverfaces Commented
hugh_nguyen_82 said:
Hi Manfred,

Yes, the problem is exactly the same as GLASSFISH-20778.
However, the fix in GLASSFISH-20778 is for JSP version of ScopedAttributedELResolver (package javax.servlet.jsp.el). Wouldn't JSF need to implement the fix too?

Furthermore, the change for ScopedAttributedELResolver alone is not enough. After resolving the class name, the field name was still not resolved correctly without using the correct chain in DemuxCompositeELResolver.

Admittedly, I know very little about how different modules (e.g. glashfish EL and mojarra impl) should work together. Please give me some pointer if I'm doing things the wrong way. Thank you for your help.

-Hugh

[ren-zhijun-oracle]

@javaserverfaces Commented
@manfredriem said:
Hi Hugh,

Thanks for reading the GLASSFISH issue. I reread it too and you might be right. Since it is clear (to us) that it is an EL issue you will need to file an issue at either the GLASSFISH issue tracker, or the EL issue tracker. I would recommend mentioning both this issue and the GLASSFISH issue.

Thanks!
Manfred

[ren-zhijun-oracle]

@javaserverfaces Commented
hugh_nguyen_82 said:
Hi Manfred,

Thank you for your advice.

I agree that this issue should be handled by EL team. My proposed fix above would create an unnecessary hard-wired dependency on EL 3.0.

So attempted to fix it from EL side. I patched AstIdentifier to resolve the class name before passing down to JSF resolver chain. That works fine. Now the class name (e.g. Boolean) is resolved. I will submit this patch on AstIdentifier to the EL team.

However, for the field resolution, EL really must pass down to JSF resolver chain. But DemuxCompositeELResolver._propertyELResolvers doesn't have the necessary StaticFieldELResolver in it. Digging a bit deeper, I think that Mojarra's ELUtils.addEL3_0_Resolvers() should add the StaticFieldELResolver to the _propertyELResolvers too (it's already added to rootELResolvers chain)

My proposal is as follow: in ELUtils.addEL3_0_Resolvers()
change from
composite.addPropertyELResolver((ELResolver) ReflectionUtils.newInstance("javax.el.StaticFieldELResolver")); which adds StaticFieldELResolver to just the root chain,
to
composite.add((ELResolver) ReflectionUtils.newInstance("javax.el.StaticFieldELResolver")); which would add the StaticELResolver to both chains.

Please consider my proposal.

Thank you for your time.

Hugh

[ren-zhijun-oracle]

@javaserverfaces Commented
@manfredriem said:
Hi Hugh,

Please file the issue at the EL side and lets go from there.

Thanks!

[ren-zhijun-oracle]

@javaserverfaces Commented
hugh_nguyen_82 said:
Ah, yes, I've filed it earlier today, UEL-40

[ren-zhijun-oracle]

@javaserverfaces Commented
hugh_nguyen_82 said:
Hi Manfred,

It seems that the EL people are too busy at the moment to respond.

Anyway, it's easy to workaround the issue on the EL side, simply by creating a custom TagHandler to do the importing of the classes.
But the field resolution can't be handled by EL side. Please consider my fix proposal. Anyway, I made a typo mistake in my fix in the previous comment, so I'll retype it here:

in:
ELUtils.addEL3_0_Resolvers():

change from:
composite.addRootELResolver((ELResolver) ReflectionUtils.newInstance("javax.el.StaticFieldELResolver"));

to:
composite.add((ELResolver) ReflectionUtils.newInstance("javax.el.StaticFieldELResolver"));

Thank you for your time.

Hugh

[ren-zhijun-oracle]

@javaserverfaces Commented
@manfredriem said:
Hugh,

Unfortunately I am not allowed to add it to the default JSF runtime, but you can add a custom EL resolver using a faces-config.xml entry. Can you try that?

Thanks!

[ren-zhijun-oracle]

@javaserverfaces Commented
hugh_nguyen_82 said:
Hi Manfred,

Thank you for your advice.

Actually, I don't even need a custom EL resolver, just adding
javax.el.StaticFieldELResolver
to faces-config.xml would do the trick.

But I was hoping for a fix at the root cause, instead of a workaround.

What is the proper procedure to fix an issue like this?
It's a clearly and easily reproduceable issue.

I have investigated it, and proposed a solution in 2 parts: 1 part for EL team, and 1 part for Mojarra.
I would welcome any comments and advice to point out that the proposed solution is inadequate in someway and therefore could not be accepted, and then I would be glad investigate further to provide an adequate solution.

I really like JSF and hope to be able to contribute to make it better.

–
Regards,
Hugh

[ren-zhijun-oracle]

@javaserverfaces Commented
This issue was imported from java.net JIRA JAVASERVERFACES-3362

[ren-zhijun-oracle]

• Issue Imported From: https://github.com/javaserverfaces/mojarra/issues/3366
• Original Issue Raised By:@javaserverfaces
• Original Issue Assigned To: @manfredriem
• Original Issue Closed By:@javaserverfaces