You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@tapestry.apache.org by "Alexander Gavrilov (Commented) (JIRA)" <ji...@apache.org> on 2012/01/24 19:00:41 UTC

[jira] [Commented] (TAP5-1493) Property expressions on properties that are covariant on a base class use the type of the base class property, not the covariant subclass

    [ https://issues.apache.org/jira/browse/TAP5-1493?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13192314#comment-13192314 ] 

Alexander Gavrilov commented on TAP5-1493:
------------------------------------------

See java.lang.Method.isBridge()
Class should have two methods with the same name and with different return types. One of them should me marked as a bridge. http://stackoverflow.com/questions/289731/what-java-lang-reflect-method-isbridge-used-for Our task is to filter bridge method out and use bridged one 
                
> Property expressions on properties that are covariant on a base class use the type of the base class property, not the covariant subclass
> -----------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: TAP5-1493
>                 URL: https://issues.apache.org/jira/browse/TAP5-1493
>             Project: Tapestry 5
>          Issue Type: Bug
>          Components: tapestry-core, tapestry-ioc
>    Affects Versions: 5.2
>            Reporter: Howard M. Lewis Ship
>            Priority: Critical
>
> public abstract class AbstractFoo
> {
>  public abstract AbstractBar getBar();
> }
> public class Foo extends AbstractFoo
> {
>  public Bar getBar();
> }
> Here property bar is covariant; the subclass (Foo) changes the type of the return value (from AbstractBar to just Bar). Assuming that Bar is a subclass of AbstractBar, that's fine.
> The bug is that in this circumstance, the PropertyConduitSource sees the type of
> property "bar" of class Foo as AbstractBar, not Bar.
> Interestingly, a little debugging showed that the getter method for property bar was "public AbstractBar Foo.getBar()" ... in other words, much like with Generics, covariant return types may be largely
> a fiction of the compiler inserting the necessary casts in place.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira