[
https://issues.apache.org/jira/browse/JCR-1402?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12573670#action_12573670
]
Stefan Guggisberg commented on JCR-1402:
----------------------------------------
> Another idea I recently had:
>
> Implement Path.getAncestor(n) by adding n parent elements to the end of the
> path. That way the ancestor is defined for any path. normalized or not,
> relative or absolute.
while i think it's an elegant approach and the result would be certainly
correct i don't think it's what the api consumer needs.
Path.getAncestor(int) is heavily used in jackrabbit core. here's a common usage
pattern:
parentPath = targetPath.getAncestor(1);
parentId = hierMgr.resolveNodePath(parentPath);
the suggested approach would probably not improve efficiency ;)
i'm further afraid that the change could break the current
CachingHierarchyManager implementation;
here's a usage example:
PathMap.Element parent = pathCache.map(path.getAncestor(1), true);
i'd therefore prefer angela's suggestion.
>
> Implement Path.isAncestorOf as follows: (isDescendant is similar)
>
> - if not both paths are either relative or absolute, throw some exception.
> - If both paths are relative determine their depths n and m. Say n < m. If n
> < 0, add -n arbitrary elements at the beginning of both paths.
> Normalize the paths and check if this paths elements are a prefix of that
> paths elements.
>
> With this approach the interface will not have to change and the
> implementation will be correct (i.e. isAncestor(getAncestor()) == true) for
> every path accepted by those methods. There might be a compatibility issue
> with implementations which rely on the current behavior of getAncestor
> returning ../ when called with ../../ However, I think this should be fixed
> in the implementation rather than keeping a core interface with a 'bogus'
> specification.
> Path.getAncestor and Path.isAncestor are not symmetric
> ------------------------------------------------------
>
> Key: JCR-1402
> URL: https://issues.apache.org/jira/browse/JCR-1402
> Project: Jackrabbit
> Issue Type: Improvement
> Components: jackrabbit-spi, jackrabbit-spi-commons
> Affects Versions: 1.4
> Reporter: Michael Dürig
> Priority: Minor
> Attachments: path.patch
>
>
> Although the method names refer to ancestors they operate on sub-paths.
> Consider:
> PathFactory pf = PathFactoryImpl.getInstance();
> Path.Element p = pf.getParentElement();
> Path path = pf.create(new Path.Element[]{p, p});
> Path ancestor = path.getAncestor(1);
> assertFalse(ancestor.isAncestorOf(path) )
> This is not what one would expect from looking an the method signatures.
> I suggest to rename getAncestor to getSubPath, clarify the javadoc, and
> deprecate getAncestorCount.
> A patch follows.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
