[jira] [Resolved] (CONFIGURATION-444) SubsetConfiguration does not properly handle interpolation when used on a HierarchicalConfiguration

["Fabien Nisol (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CONFIGURATION-444?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Fabien Nisol resolved CONFIGURATION-444.
----------------------------------------

    Resolution: Not A Problem

The SubsetConfiguration should not be directly used as stated in comments

> SubsetConfiguration does not properly handle interpolation when used on a HierarchicalConfiguration
> ---------------------------------------------------------------------------------------------------
>
>                 Key: CONFIGURATION-444
>                 URL: https://issues.apache.org/jira/browse/CONFIGURATION-444
>             Project: Commons Configuration
>          Issue Type: Bug
>          Components: Interpolation
>    Affects Versions: 1.6
>         Environment: all
>            Reporter: Fabien Nisol
>
> Imaging next text files:
> {code:xml}
> <properties>
> 	<var>a_value</var>
> 	<prop2>
> 		<prop
> 			attr1="${var}"
> 			attr2="attr2"
> 		/>
> 	</prop2>
> </properties>
> {code}
> {code:java}
> ...
>   XMLConfiguration config2 = new XMLConfiguration("test/test2.xml");
>   Configuration subset2 = config2.subset("prop2");
>   Configuration subset3 = new SubsetConfiguration(subset2,"prop");
>   System.err.println(subset3.getString("[@attr1]"))
> ...
> {code}
> the result is wrong:
> {code}
> ${var}
> {code}
> it should be:
> {code}
> a_value
> {code}
> I think the problem is related to the _interpolate()_ method in SubsetConfiguration(), which seems to involve some kind of recursive trick that seem overcomplicated (and inefficient, since it's creating unnecessary SubsetConfiguration)..
> But maybe I'm missing something.
> {code}
>     protected Object interpolate(Object base)
>     {
>         if (delimiter == null && "".equals(prefix))
>         {
>             return super.interpolate(base);
>         }
>         else
>         {
>             SubsetConfiguration config = new SubsetConfiguration(parent, "");
>             return config.interpolate(base);
>         }
>     }
> {code}
> I think the code below would be more appropriate:
> {code}
>     protected Object interpolate(Object base)
>     {
>         if(parent instanceof AbstractConfiguration)
>         {
>             return ((AbstractConfiguration)parent).interpolate(base);
>         } else {
>             return base;
>         }
>     }
> {code}
> There's no reason to try interpolation if the parent is not implementing interpolation. 
> This brings other questions about the whole interpolation thing. I really wonder why the _Configuration_ interface does not define that method, leaving or the the option to implementation to actually implement it. But that is another debate.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira