/* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.xmlbeans.impl.xpath.saxon;
import org.apache.xmlbeans.impl.store.SaxonXBeansDelegate;
import org.w3c.dom.Node;
import java.util.List;
import java.util.Map;
import java.util.ListIterator;
import javax.xml.transform.TransformerException;
import net.sf.saxon.Configuration;
import net.sf.saxon.dom.NodeOverNodeInfo;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.sxpath.XPathEvaluator;
import net.sf.saxon.sxpath.XPathExpression;
import net.sf.saxon.trans.Variable;
import javax.xml.transform.dom.DOMSource;
public class XBeansXPath
implements SaxonXBeansDelegate.SelectPathInterface {
/**
* Construct given an XPath expression string.
* @param xpathExpr The XPath expression.
* @param contextVar The name of the context variable
* @param namespaceMap a map of prefix/uri bindings for NS support
* @param defaultNS the uri for the default element NS, if any
*/
public XBeansXPath(String xpathExpr, String contextVar,
Map namespaceMap, String defaultNS)
{
_queryExpr = xpathExpr;
_contextVar = contextVar;
this.defaultNS = defaultNS;
this.namespaceMap = namespaceMap.entrySet().toArray();
this.needsDomSourceWrapping = needsDOMSourceWrapping();
}
/**
* Select all nodes that are selectable by this XPath
* expression. If multiple nodes match, multiple nodes
* will be returned.
* <p/>
* <p/>
* <b>NOTE:</b> In most cases, nodes will be returned
* in document-order, as defined by the XML Canonicalization
* specification. The exception occurs when using XPath
* expressions involving the <code>union</code> operator
* (denoted with the pipe '|' character).
* </p>
* <p/>
* <p/>
* <b>NOTE:</b> Param node must be a Dom node which will be used during the xpath
* execution and iteration through the results. A call of node.dispose() must be done
* after reading all results.
* </p>
*
* @param node The node, nodeset or Context object for evaluation.
* This value can be null.
* @return The <code>a list</code> of all items selected
* by this XPath expression.
*/
public List selectNodes(Object node)
{
try
{
DOMSource rootNode = new DOMSource((Node) node);
XPathEvaluator xpe = new XPathEvaluator();
Configuration c = new Configuration();
c.setTreeModel(net.sf.saxon.event.Builder.STANDARD_TREE);
XBeansIndependentContext sc = new XBeansIndependentContext(c);
// Declare ns bindings
if (defaultNS != null)
sc.setDefaultElementNamespace(defaultNS);
for (int i = 0; i < namespaceMap.length; i++)
{
Map.Entry entry = (Map.Entry) namespaceMap[i];
sc.declareNamespace((String) entry.getKey(),
(String) entry.getValue());
}
xpe.setStaticContext(sc);
Variable thisVar = sc.declareVariable(_contextVar);
thisVar.setValue(needsDomSourceWrapping ? rootNode : node);
XPathExpression exp = xpe.createExpression(_queryExpr);
// After 8.3(?) Saxon nodes no longer implement Dom.
// The client needs saxon8-dom.jar, and the code needs
// this NodeOverNodeInfo Dom wrapper doohickey
List saxonNodes = exp.evaluate(rootNode);
for (ListIterator it = saxonNodes.listIterator(); it.hasNext();)
{
Object o = it.next();
if(o instanceof NodeInfo)
{
Node n = NodeOverNodeInfo.wrap((NodeInfo)o);
it.set(n);
}
}
return saxonNodes;
}
catch (TransformerException e)
{
throw new RuntimeException(e);
}
}
public List selectPath(Object node)
{
return selectNodes(node);
}
/**
* @return true if we are dealing with a version of Saxon 8.x where x<=6
*/
private static boolean needsDOMSourceWrapping()
{
int saxonMinorVersion;
int saxonMajorVersion;
String versionString = net.sf.saxon.Version.getProductVersion();
int dot1 = versionString.indexOf('.');
if (dot1 < 0)
return false;
int dot2 = versionString.indexOf('.', dot1 + 1);
if (dot2 < 0)
return false;
try
{
saxonMajorVersion = Integer.parseInt(versionString.substring(0, dot1));
saxonMinorVersion = Integer.parseInt(versionString.substring(dot1 + 1, dot2));
return saxonMajorVersion == 8 && saxonMinorVersion <= 6;
}
catch (NumberFormatException nfe)
{
return false;
}
}
private boolean needsDomSourceWrapping;
private Object[] namespaceMap;
private String _queryExpr;
private String _contextVar;
private String defaultNS;
}