Legacy ID: #5187031
Legacy Poster: David (pagod)
Hi, I want to write an XSLT extension function in Java using the Saxon API, and
before I start to do that I wanted to experiment a bit with Saxon's data structures.
I've been playing with this XPathExample.java provided in the samples with Saxon
9.0.0.4J, and tried it on this othello.xml file. It works fine, no problem. Then after I
had stripped it a bit I wanted to try it on a file of mine. I've modified only the go
function, it now looks like this: public void go(String filename) throws Exception {
System.setProperty( "javax.xml.xpath.XPathFactory:" +
NamespaceConstant.OBJECT_MODEL_SAXON,
"net.sf.saxon.xpath.XPathFactoryImpl"); XPathFactory xpf =
XPathFactory.newInstance(NamespaceConstant.OBJECT_MODEL_SAXON); XPath xpe =
xpf.newXPath(); InputSource is = new InputSource(new File(filename).toURL().toString());
SAXSource ss = new SAXSource(is); NodeInfo doc = ((XPathEvaluator)xpe).setSource(ss);
xpe.setXPathVariableResolver(this); XPathExpression findLine =
xpe.compile("//LINE"); List matchedLines =
(List)findLine.evaluate(doc, XPathConstants.NODESET); TinyNodeImplelement; inti = 0;
for( Iterator< TinyNodeImpl > it = matchedLines.iterator() ; it.hasNext()
; i++ ) { element = (net.sf.saxon.tinytree.TinyNodeImpl)( it.next() );
System.err.println( i + ": " + element.getDisplayName() ); } } not
much left, and it still works fine on othello.xml -- it displays 3556 times
"LINE", which is OK. now I've tried this code on a file of mine. it's
a small svg file: <?xml version="1.0"?> <svg
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink"
width="453.55pt" height="310.75pt"
viewBox="1134 1418 15695 10754 "> <g
id="_x0000_s1053"> <g
id="_x0000_s1059"> <svg x="5682"
y="5038" width="636" height="484"
viewBox="0 0 21600 21600" preserveAspectRatio="none"
fill="white" stroke="cyan"
stroke-width="1000pt" opacity="1"
overflow="visible"> <path d="M 10800,0 L
0,10800 10800,21600 21600,10800 z "/> </svg>
</g> <g transform=" translate(12012 0) matrix(-1 0 0 1 0
0) rotate(90 6006 5921)" id="_x0000_s1073">
<svg x="5606" y="5917"
width="800" height="9" viewBox="0 0 21600
21600" preserveAspectRatio="none"
fill="none" stroke="purple"
stroke-width="1000pt" opacity="1"
overflow="visible"> <path d="M 0,0 L 0,0
0,21600 21600,21600 "/> </svg> </g>
<g id="_x0000_s1104"> <svg
x="5224" y="6321" width="1569"
height="485" viewBox="0 0 21600 21600"
preserveAspectRatio="none" fill="white"
stroke="red" stroke-width="1000pt"
opacity="1" overflow="visible"> <path
d="M 0,0 L 0,21600 l 21600,0 L 21600,0 z "/>
</svg> </g> </g> </svg> and I've
changed the XPath expression "//LINE" into "//g".
and well, i don't get any results! :-o if i use "//" as the
expression, i get all the nodes in the tree, but "/svg",
"//svg", "/" and so on don't work either. what am i
doing wrong??? i can't see any difference between my file and othello.xml (besides the
obvious), and i have absolutely no clue why my XPath expressions (well, most of them at
least) don't work, while obviously it has managed to read and parse the file. it'd be
real cool if someone could try it and tell me what they get -- or simply explain what
stupid mistake i may have made here! i'm running the Java program in eclipse with java
1.5.0_05. Thanks a lot! David
XPath::compile & XPathExpression::evaluate
.