Axiom uses Jaxen for its XPath support because Jaxen has an abstraction layer that allows to plug in any object model. The javax.xml.xpath API is also designed to support multiple object models, however AFAIK existing implementations only support DOM. That means that one would have to convert the entire message to DOM every time an XPath expression is evaluated. Obviously that is not a good thing to do.
Since building and maintaining an XPath 2.0 implementation is out of the scope of the Axiom project, this leaves us with two reasonable options: 1. Find an existing XPath 2.0 implementation that has the same level of object model independence as Jaxen. If such an implementation exists, one would only have to write the glue code to integrate it with Axiom. 2. Use an Axiom implementation that not only implements enough of the Axiom API to support the Axis2 and Synapse runtime, but also provides a decent implementation of the DOM API so that an existing implementation of the javax.xml.xpath API can be used. This is not the case for DOOM: it doesn't implement the Axiom API well enough to run Axis2. I've been working for some time on a project [1] that provides this kind of implementation. It is making steady progress, but it is still very experimental and is only able to run some parts of the Axis2 runtime. Andreas [1] http://code.google.com/p/ddom/ On Fri, Jul 15, 2011 at 05:01, indika kumara <indika.k...@gmail.com> wrote: > Heshan, I think the better option is to use the standard > javax.xml.xpath API, and try to avoid AXIOMXPath. It seems that saxon > supports javax.xml.xpath API. It should be a matter of configuring a > property to force to use Saxon implementation - just like XSLT > transformation, Schema validation. > > There may be a trade-off between flexibility and performance with the > selection of a standard API or AXIOMXPath. However, with OMSource > [3-4] or similar thing, you should be able to plug AXIOM XML model to > the XPATH engine in a standard way. So, effectively, you may be able > to get any performance gain (if there are) from the use of AXIOMXPath > with the standard way too. BTW, anything needs to be validated. > > Thanks, > > Indika > > [1] > http://download.oracle.com/javase/1.5.0/docs/api/javax/xml/xpath/package-frame.html > [2] http://www.saxonica.com/documentation/javadoc/index.html > [3] > http://svn.apache.org/viewvc/synapse/trunk/java/modules/core/src/main/java/org/apache/synapse/util/jaxp/ > [4] > http://ws.apache.org/axiom/apidocs/org/apache/axiom/om/impl/jaxp/OMSource.html > > On Fri, Jul 15, 2011 at 12:15 PM, Heshan Suriyaarachchi > <heshan.suriyaarach...@gmail.com> wrote: >> Hi Devs, >> Synapse currently does not support XPath 2.0. I am looking into a way of >> adding this support for Synapse. >> SynapseXPath is written by extending AXIOMXPath which is using Jaxen. Jaxen >> does not support XPath 2.0. That is the reason that we can not use XPath 2.0 >> in Synapse. >> I would like to get your valuable feedback on the way to go with $subject. >> >> [1] >> - http://mail-archives.apache.org/mod_mbox/ws-dev/201107.mbox/%3ccamtot2qsuf2vb7pas_hln29_k3anwnywyceolq_s6ygtaas...@mail.gmail.com%3E >> [2] - https://issues.apache.org/jira/browse/AXIOM-367 >> -- >> Regards, >> Heshan Suriyaarachchi >> >> http://heshans.blogspot.com/ >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@synapse.apache.org > For additional commands, e-mail: dev-h...@synapse.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@synapse.apache.org For additional commands, e-mail: dev-h...@synapse.apache.org
