I too have had a go at this, but I too am not an XPath expert. First of all make sure you have _all of_ saxon8.jar and saxon8-dom.jar and xbean_xpath.jar (in addition to the normal xbean.jar and the JSR 173 jar) on your classpath. Not having saxon8-dom.jar can cause strange errors. Not having xbean_xpath.jar just means that no XPath will work.
Other than that I think it might just be that we're not passing in the right XPath. Siegfried, can you attach an example XML instance document for which you are expecting this to work? Here's the one I tried: <elem1 xmlns=\"http://laj.org/test\"; > <elem11 id=\"123\" >text11</elem11> <elem21 id=\"456\" >text11</elem21> <elem12 idRef=\"123\" /> <elem13 idRef=\"456\" /> <elem14 idRef=\"123\" /> <elem15 idRef=\"456\" /> <elem16 idRef=\"123\" /> <elem17 idRef=\"789\" /> </elem1> And here are the issues I see. 1. The element on which you perform the selectPath() call seems to represent the root as far as the call to selectPath() is concerned. So if e.g. you passed in only the XmlObject for <elem11> above you should not expect any of the other elements to be returned regardless of the XPath passed in. 2. But it is likely that the elements with idRef in them are _not_ children of the element with id in them. Rather it is likely that they are all members of some larger document element such as <elem1> above. So to get the selectPath() to even consider them you would need to pass in the XmlObject for <elem1> (or at least some element that is a root to all of the results you expect). 3. But then the path to the id attribute is no longer $this/@id as that would only match the _root_ element (<elem1> in this case) having an id attribute. Exactly what you need to pass in depends on what you want to do - if you want to find all idRefs that match _any_ id attribute anywhere in the document then you probably want $this//@id instead. 4. I tried the XPath //[EMAIL PROTECTED]//@id] on the complete document above (i.e. I executed selectPath() on the XmlObject representing <elem1>) and printed out the list of XmlObjects returned from selectPath(). I got: Number of results = 5 results[0] = <xml-fragment idRef="123"/> results[1] = <xml-fragment idRef="456"/> results[2] = <xml-fragment idRef="123"/> results[3] = <xml-fragment idRef="456"/> results[4] = <xml-fragment idRef="123"/> which is what I'd expect i.e. I get all the nodes with an idRef that matches any id attribute somewhere else in the document (and I don't get those that do not match). Not sure why they are xml-fragment's rather than proper individual elements with proper QNames but that's a different issue. 5. Note that replacing '$this' with '.' (i.e. XPath = //[EMAIL PROTECTED]//@id) gave me an empty result set. My guess is that '.' is evaluated dynamically (i.e. it means the current node that the query has evaluated to) compared to $this which is bound statically at the beginning to the root node that you pass in. (With the '.' version of the XPath I think you are looking for a node which has both an id and an idRef attribute where the values are the same - which is a slightly different query.) I haven't tried this exhaustively - I'm not sure what would happen if some of the id or idRef attributes were on elements at deeper levels. But anyway I hope that helps get started. Cheers, Lawrence > -----Original Message----- > From: Radu Preotiuc-Pietro > Sent: Thursday, March 30, 2006 1:56 PM > To: [email protected] > Subject: RE: selectPath with FilterExpression using $this > > I was curious to try this myself with the new Saxon 8.6 integration > (available from the SVN head only, for the moment) and what I found is > that the path you are suggesting ("//[EMAIL PROTECTED]/@id]") works (no > exception) but for some reason doesn't return anything. On the other > hand, "//[EMAIL PROTECTED]'1'" returns the expected result, so on one hand I am > wondering if this is maybe a bug in the free version of Saxon and on the > other you can use this to workaround the problem by doing > .selectPath("//[EMAIL PROTECTED]'" + node.getId() + "'"). > > If anyone else has other insights into why the original path does not > work (with more Xpath/Saxon knowledge), I'd also be interested to know. > > Thanks, > Radu > > -----Original Message----- > From: Cezar Andrei > Sent: Wednesday, March 29, 2006 3:30 PM > To: [email protected] > Subject: RE: selectPath with FilterExpression using $this > > Hi Siegfried, > > I'm not an expert in xpath/xquery but I'm pretty sure that $this doesn't > represent the internal current node that is processed by the engine. > > So you'll probably want to rewrite the expression to something like > this: > xo.selectPath(".//[EMAIL PROTECTED]//@id]"); > > As for $this, it's just a variable that is bound to the XmlObject that > you are calling the selectPath method from. The '$this' construction is > not in the latest XPath/Xquery spec so it was deprecated, instead "." > should be used. > > The current XmlObject can be bound to any user specified variable name > as in the following example: > > XmlOptions options = new XmlOptions(); > options.setXqueryCurrentNodeVar("myVariable"); > XmlObject[] res = xo.selectPath("declare variable $myVariable > external; $myVariable//el1", options); > > Which is equivalent to: > > XmlObject[] res = xo.selectPath(".//el1", options); > > And to the following (since in the context of the xpath engine the xo is > considered the root): > > XmlObject[] res = xo.selectPath("//el1", options); > > Since we don't control Saxon, we can't promise that expressions > confirming to the spec will work. We can only work on making sure we > make the right calls into Saxon. > > Cezar > > > > -----Original Message----- > > From: Siegfried Baiz [mailto:[EMAIL PROTECTED] > > Sent: Tuesday, March 14, 2006 12:11 PM > > To: [email protected] > > Subject: selectPath with FilterExpression using $this > > > > Hello, > > > > for a given XmlObject xo with an ID-Attribute 'id', I've tried to > > launch the following xpath-expression: > > > > xo.selectPath("//[EMAIL PROTECTED]/@id]") > > > > in order to get all nodes (with idRef-Attribute) refering to my node > xo. > > > > Unfortunatlly this expression seems not to work. I always get an > > java.lang.ArrayIndexOutOfBoundsException from the underlying > > > net.sf.saxon.expr.XPathContextMajor.setLocalVariable(XPathContextMajor.j > av > > a:213) > > > > At > > > http://xmlbeans.apache.org/docs/2.0.0/guide/conSelectingXMLwithXQueryPat > hX > > Path.html > > I found the following notice: > > "Notice in the query expression that the variable $this > represents > > the current context node (the XmlObject that you are querying > from). > > In this example you are querying from the document level > XmlObject." > > > > After reading that sentence I've been thinking, that $this is somehow > > similar to "curent()" in XSLT, but maybe a got the meaning wrong. > > > > Does anyone know whats the problem here rsp. > > is there a better way to accomplish the same thing? > > > > Thanks a lot, > > > > Siggi > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > _______________________________________________________________________ > Notice: This email message, together with any attachments, may contain > information of BEA Systems, Inc., its subsidiaries and affiliated > entities, that may be confidential, proprietary, copyrighted and/or > legally privileged, and is intended solely for the use of the individual > or entity named in this message. 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