The dialect detection now covers the following versions of XLXP: - The version from the Web Services Feature pack. - IBM JDK 1.6. - WebSphere 7
In particular it fixes the setPrefix behavior of the early XLXP versions, so that I was able to eliminate the isSetPrefixBeforeStartElement stuff. All Axiom tests succeed with the three versions. Please review and let me know if there are any concerns. Andreas On Tue, Jul 28, 2009 at 15:04, Davanum Srinivas<[email protected]> wrote: > Andreas, > > I have no clue what happens in the StaX JSR mailing lists...All i know is > that there are variations between the stax impl(s) currently in the field > and this is the only check where we could not find a better way to manage > the variations cleanly. Which is why the dialect stuff introduction is a > good thing :) > > thanks, > -- dims > > On 07/28/2009 08:33 AM, Andreas Veithen wrote: >> >> Dims, >> >> I just stumbled over TUSCANY-1818. When reading this together with >> WSCOMMONS-66 and WSCOMMONS-262, things become clearer. Apparently, >> what happened is that in the first versions of XLXP-J, IBM didn't get >> the StAX specs right and Axiom had to adapt to this, i.e. the vague >> term "user community" actually refers to IBM! When they finally >> recognized this problem, they introduced the >> javax.xml.stream.XMLStreamWriter.isSetPrefixBeforeStartElement >> property as an elegant way to rectify this without making too much >> noise. Brilliant! >> >> Andreas >> >> On Tue, Jul 28, 2009 at 09:21, Andreas Veithen<[email protected]> >> wrote: >>> >>> Dims, >>> >>> Actually I initially developed the idea to have the concept of a "StAX >>> dialect" in Axiom when I saw this piece of code. I started to >>> implement this feature when trying to solve the thread safety issue, >>> but the aim is clearly to get rid of the isSetPrefixBeforeStartElement >>> hack(s). >>> >>> I had a closer look at the code during the weekend, but I fail to see >>> in which case we would actually need/have >>> isSetPrefixBeforeStartElement == true. In my opinion, the StAX >>> specifications don't leave enough room for the second interpretation >>> (that setPrefix would apply to the next writeStartElement) [1]. Also, >>> of all the StAX implementations I've seen, none expects this. Do you >>> have any idea which "user community" "believes" this? >>> >>> Andreas >>> >>> [1] http://people.apache.org/~veithen/axiom/devguide/ch02.html#d0e69 >>> >>> On Tue, Jul 28, 2009 at 00:45, Davanum Srinivas<[email protected]> >>> wrote: >>>> >>>> Andreas, >>>> >>>> Not sure if you have seen this already. There's some convoluted code >>>> in org/apache/axiom/om/impl/util/OMSerializerUtil.java (method >>>> isSetPrefixBeforeStartElement) which basically has a toggle based on >>>> the parsers. >>>> >>>> // Fallback: Toggle based on sun or woodstox implementation. >>>> NamespaceContext nc = writer.getNamespaceContext(); >>>> ret = (nc == null || >>>> (nc.getClass().getName().indexOf("wstx") == -1&& >>>> nc.getClass().getName().indexOf("weblogic") >>>> == -1&& >>>> nc.getClass().getName().indexOf("sun") == >>>> -1)); >>>> >>>> The javadoc has more information: >>>> >>>> /** >>>> * Unfortunately there is disagreement in the user community about >>>> the semantics of setPrefix on >>>> * the XMLStreamWriter. An example will explain the difference: >>>> writer.startElement("a") >>>> * writer.setPrefix("pre", "urn://sample") writer.startElement("b") >>>> *<p/> >>>> * Some user communities (woodstox) believe that the setPrefix is >>>> associate with the scope for >>>> * "a" and thus remains in scope until the end of a. The basis >>>> for this believe is >>>> * XMLStreamWriter javadoc (which some would argue is incomplete). >>>> *<p/> >>>> * Some user communities believe that the setPrefix is associated >>>> with the "b" element. These >>>> * communities reference an example in the specification and >>>> historical usage of SAX. >>>> *<p/> >>>> * This method will return true if the setPrefix is associated >>>> with the next writeStartElement. >>>> * >>>> * @param writer >>>> * @return true if setPrefix should be generated before startElement >>>> */ >>>> >>>> Can you please take a look? >>>> >>>> If we can find a way to totally remove the need for caching the >>>> boolean after checking the xmlstreamwriter, that would be a big bonus. >>>> >>>> thanks, >>>> dims >>>> >>>> -- >>>> Davanum Srinivas :: http://davanum.wordpress.com >>>> >
