On Sun, Apr 7, 2013 at 11:49 AM, Amila Suriarachchi <[email protected]> wrote: > > > > On Mon, Apr 1, 2013 at 12:14 PM, Andreas Veithen <[email protected]> > wrote: >> >> On Sun, Mar 24, 2013 at 9:19 AM, Isuru Ranawaka <[email protected]> >> wrote: >> > 1. ) Streaming Xpath Parser is developed for a ESB which get AXIOM >> > Object >> > and traverse through it and get results.here the main concern is to >> > improve >> > the performance of xpath parsing by specifying specific rules relevant >> > to >> > the domain. (e.g if there is expression such as “/data/book” it only >> > give >> > the first child element under the data element ) what i suggest is >> > creating >> > a XpathEngine which does not consume any external object model and it >> > will >> > operate on top of the XML Stream that means traverse xmlstream and >> > evaluate >> > xpath. >> >> Can you explain how this would work for an expression like >> /data/book[isbn='1-84356-028-3']? > > > Let me give an expiation for this. > > For that scenario it won't work. There is no way to verify whether there is > an element matching unless it reads the whole xml stream. > > But scenarios like /data/book[1] it will work. the assumption here is that > ESBs like synapse it may not required to build the whole envelop to process > the xpaths always. For such cases it would give a performance advantage.
According to Isuru the "XPath" implementation would operate on an XMLStreamReader. That means that after evaluating the expression, everything before /data/book[1] will have been discarded. How would Synapse manage the case where a subsequent mediator in the same mediation attempts to access that part of the message? > thanks, > Amila. >> >> >> Andreas >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [email protected] >> For additional commands, e-mail: [email protected] >> > > > > -- > Amila Suriarachchi > WSO2 Inc. > blog: http://amilachinthaka.blogspot.com/ --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
