On Fri, Jul 9, 2010 at 12:51 PM, Jeremy Boynes <jboy...@apache.org> wrote: > In light of the performance issues logged against the XML taglib and > functional issues like #49578, I was looking at refactor the XML tags to use > the JAXP XPath API to pre-compile expressions and dynamically resolve > variables. I think this can be done fairly easily and will eliminate a lot of > the integration code in XPathUtil. However, I could not see how to expose the > full iteration context described in the spec for <x:forEach>: > > * the context position is the iteration 'count' (with the same meaning as in > <c:forEach>) > * the context size is equal to the number of nodes in the node-set over which > <x:forEach> is iterating > > It looks like the current implementation does not support this: > https://issues.apache.org/bugzilla/show_bug.cgi?id=22765 > and in testing these functions always return -1 and 0 respectively. > > Presumably these should be returned by the XPath core functions position() > and last() respectively. However, the JAXP API only allows a single Node to > be passed in for evaluation and I could not see a way to provide the context > needed by these functions. I think this might be a limitation of JAXP. > > I plan to go ahead with the refactor as I think by simplifying our > implementation we will address the current performance issues and fix some of > the functional edge cases. It will also remove the hard dependency on the > Xalan implementation.The iteration context functions will remain broken > consistent with the current implementation. > > It might be possible to make this work using the low-level internal Xalan > APIs as this functionality is supported in Xalan's XSLT processing. To > support this in the future, I'll try to make the XPath usage pluggable so we > can drop in a Xalan-specific version in the future. > > Thoughts?
+1. Resolving the speed and some of the issues is worth making it harder to resolve the other issues imo. Hen --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
