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https://issues.apache.org/jira/browse/GROOVY-3942?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16343137#comment-16343137
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Jan Šmucr commented on GROOVY-3942:
-----------------------------------
Just ran into this and trying to figure out some workaround. :(
> Using metaClass to override methods in class hierarchy does not work as
> expected
> --------------------------------------------------------------------------------
>
> Key: GROOVY-3942
> URL: https://issues.apache.org/jira/browse/GROOVY-3942
> Project: Groovy
> Issue Type: Bug
> Components: groovy-runtime
> Affects Versions: 1.8-beta-1
> Environment: Windows XP
> Reporter: Alex McManus
> Priority: Major
> Attachments: MetaclassOverrideTest.groovy
>
>
> I've found some strange behaviour when dynamically overriding methods that
> are called in a class hierarchy, which I think might be a bug. The problem is
> that when I override a method on a subclass, code in the superclass still
> calls the original method (note all classes are Groovy ones, I know this
> wouldn't work with a Java class hierarchy).
> I've isolated it to this sample code:
> {code:Java}
> class BaseClass {
> def baseClassMethod() {
> println "BaseClass.baseClassMethod()"
> internalMethod()
> }
> def internalMethod() {
> println " BaseClass.internalMethod()"
> }
> }
> class SubClass extends BaseClass {
> def subClassMethod() {
> println "SubClass.subClassMethod()"
> internalMethod()
> }
> }
> def subClass = new SubClass()
> subClass.metaClass.internalMethod = { -> println ("
> (dynamic).internalMethod()")}
> subClass.baseClassMethod()
> subClass.subClassMethod()
> {code}
> ...which gives me the following output...
> BaseClass.baseClassMethod()
> BaseClass.internalMethod()
> SubClass.subClassMethod()
> (dynamic).internalMethod()
> I would have expected that the dynamic version of internalMethod() would be
> called both times, given that Groovy has dynamic method dispatching.
> Some discussion of this issue took place on the mailing list:
> http://old.nabble.com/Problems-using-metaClass-to-override-methods-in-class-hierarchy-td26743895.html#a26743895
> The suggestion is that the CallSiteArray.createCallCurrentSite(...) method
> could check whether the receiver is a sub class of the sender class.
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