/*
* Copyright 1999-2004 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.
*/
/*
* $Id: Extensions.java,v 1.2.4.1 2005/09/10 18:53:32 jeffsuttor Exp $
*/
package com.sun.org.apache.xalan.internal.lib;
import java.util.Hashtable;
import java.util.StringTokenizer;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import com.sun.org.apache.xalan.internal.extensions.ExpressionContext;
import com.sun.org.apache.xalan.internal.xslt.EnvironmentCheck;
import com.sun.org.apache.xpath.internal.NodeSet;
import com.sun.org.apache.xpath.internal.objects.XBoolean;
import com.sun.org.apache.xpath.internal.objects.XNumber;
import com.sun.org.apache.xpath.internal.objects.XObject;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.w3c.dom.traversal.NodeIterator;
import org.xml.sax.SAXNotSupportedException;
/**
* This class contains many of the Xalan-supplied extensions.
* It is accessed by specifying a namespace URI as follows:
* <pre>
* xmlns:xalan="http://xml.apache.org/xalan"
* </pre>
* @xsl.usage general
*/
public class Extensions
{
/**
* Constructor Extensions
*
*/
private Extensions(){} // Make sure class cannot be instantiated
/**
* This method is an extension that implements as a Xalan extension
* the node-set function also found in xt and saxon.
* If the argument is a Result Tree Fragment, then <code>nodeset</code>
* returns a node-set consisting of a single root node as described in
* section 11.1 of the XSLT 1.0 Recommendation. If the argument is a
* node-set, <code>nodeset</code> returns a node-set. If the argument
* is a string, number, or boolean, then <code>nodeset</code> returns
* a node-set consisting of a single root node with a single text node
* child that is the result of calling the XPath string() function on the
* passed parameter. If the argument is anything else, then a node-set
* is returned consisting of a single root node with a single text node
* child that is the result of calling the java <code>toString()</code>
* method on the passed argument.
* Most of the
* actual work here is done in <code>MethodResolver</code> and
* <code>XRTreeFrag</code>.
* @param myProcessor Context passed by the extension processor
* @param rtf Argument in the stylesheet to the nodeset extension function
*
* NEEDSDOC ($objectName$) @return
*/
public static NodeSet nodeset(ExpressionContext myProcessor, Object rtf)
{
String textNodeValue;
if (rtf instanceof NodeIterator)
{
return new NodeSet((NodeIterator) rtf);
}
else
{
if (rtf instanceof String)
{
textNodeValue = (String) rtf;
}
else if (rtf instanceof Boolean)
{
textNodeValue = new XBoolean(((Boolean) rtf).booleanValue()).str();
}
else if (rtf instanceof Double)
{
textNodeValue = new XNumber(((Double) rtf).doubleValue()).str();
}
else
{
textNodeValue = rtf.toString();
}
// This no longer will work right since the DTM.
// Document myDoc = myProcessor.getContextNode().getOwnerDocument();
try
{
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document myDoc = db.newDocument();
Text textNode = myDoc.createTextNode(textNodeValue);
DocumentFragment docFrag = myDoc.createDocumentFragment();
docFrag.appendChild(textNode);
return new NodeSet(docFrag);
}
catch(ParserConfigurationException pce)
{
throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(pce);
}
}
}
/**
* Returns the intersection of two node-sets.
*
* @param nl1 NodeList for first node-set
* @param nl2 NodeList for second node-set
* @return a NodeList containing the nodes in nl1 that are also in nl2
*
* Note: The usage of this extension function in the xalan namespace
* is deprecated. Please use the same function in the EXSLT sets extension
* (http://exslt.org/sets).
*/
public static NodeList intersection(NodeList nl1, NodeList nl2)
{
return ExsltSets.intersection(nl1, nl2);
}
/**
* Returns the difference between two node-sets.
*
* @param nl1 NodeList for first node-set
* @param nl2 NodeList for second node-set
* @return a NodeList containing the nodes in nl1 that are not in nl2
*
* Note: The usage of this extension function in the xalan namespace
* is deprecated. Please use the same function in the EXSLT sets extension
* (http://exslt.org/sets).
*/
public static NodeList difference(NodeList nl1, NodeList nl2)
{
return ExsltSets.difference(nl1, nl2);
}
/**
* Returns node-set containing distinct string values.
*
* @param nl NodeList for node-set
* @return a NodeList with nodes from nl containing distinct string values.
* In other words, if more than one node in nl contains the same string value,
* only include the first such node found.
*
* Note: The usage of this extension function in the xalan namespace
* is deprecated. Please use the same function in the EXSLT sets extension
* (http://exslt.org/sets).
*/
public static NodeList distinct(NodeList nl)
{
return ExsltSets.distinct(nl);
}
/**
* Returns true if both node-sets contain the same set of nodes.
*
* @param nl1 NodeList for first node-set
* @param nl2 NodeList for second node-set
* @return true if nl1 and nl2 contain exactly the same set of nodes.
*/
public static boolean hasSameNodes(NodeList nl1, NodeList nl2)
{
NodeSet ns1 = new NodeSet(nl1);
NodeSet ns2 = new NodeSet(nl2);
if (ns1.getLength() != ns2.getLength())
return false;
for (int i = 0; i < ns1.getLength(); i++)
{
Node n = ns1.elementAt(i);
if (!ns2.contains(n))
return false;
}
return true;
}
/**
* Returns the result of evaluating the argument as a string containing
* an XPath expression. Used where the XPath expression is not known until
* run-time. The expression is evaluated as if the run-time value of the
* argument appeared in place of the evaluate function call at compile time.
*
* @param myContext an <code>ExpressionContext</code> passed in by the
* extension mechanism. This must be an XPathContext.
* @param xpathExpr The XPath expression to be evaluated.
* @return the XObject resulting from evaluating the XPath
*
* @throws SAXNotSupportedException
*
* Note: The usage of this extension function in the xalan namespace
* is deprecated. Please use the same function in the EXSLT dynamic extension
* (http://exslt.org/dynamic).
*/
public static XObject evaluate(ExpressionContext myContext, String xpathExpr)
throws SAXNotSupportedException
{
return ExsltDynamic.evaluate(myContext, xpathExpr);
}
/**
* Returns a NodeSet containing one text node for each token in the first argument.
* Delimiters are specified in the second argument.
* Tokens are determined by a call to <code>StringTokenizer</code>.
* If the first argument is an empty string or contains only delimiters, the result
* will be an empty NodeSet.
*
* Contributed to XalanJ1 by <a href="mailto:benoit.cerrina@writeme.com">Benoit Cerrina</a>.
*
* @param toTokenize The string to be split into text tokens.
* @param delims The delimiters to use.
* @return a NodeSet as described above.
*/
public static NodeList tokenize(String toTokenize, String delims)
{
Document doc = DocumentHolder.m_doc;
StringTokenizer lTokenizer = new StringTokenizer(toTokenize, delims);
NodeSet resultSet = new NodeSet();
synchronized (doc)
{
while (lTokenizer.hasMoreTokens())
{
resultSet.addNode(doc.createTextNode(lTokenizer.nextToken()));
}
}
return resultSet;
}
/**
* Returns a NodeSet containing one text node for each token in the first argument.
* Delimiters are whitespace. That is, the delimiters that are used are tab (	),
* linefeed (
), return (
), and space ( ).
* Tokens are determined by a call to <code>StringTokenizer</code>.
* If the first argument is an empty string or contains only delimiters, the result
* will be an empty NodeSet.
*
* Contributed to XalanJ1 by <a href="mailto:benoit.cerrina@writeme.com">Benoit Cerrina</a>.
*
* @param toTokenize The string to be split into text tokens.
* @return a NodeSet as described above.
*/
public static NodeList tokenize(String toTokenize)
{
return tokenize(toTokenize, " \t\n\r");
}
/**
* Return a Node of basic debugging information from the
* EnvironmentCheck utility about the Java environment.
*
* <p>Simply calls the {@link com.sun.org.apache.xalan.internal.xslt.EnvironmentCheck}
* utility to grab info about the Java environment and CLASSPATH,
* etc., and then returns the resulting Node. Stylesheets can
* then maniuplate this data or simply xsl:copy-of the Node. Note
* that we first attempt to load the more advanced
* org.apache.env.Which utility by reflection; only if that fails
* to we still use the internal version. Which is available from
* <a href="http://xml.apache.org/commons/">http://xml.apache.org/commons/</a>.</p>
*
* <p>We throw a WrappedRuntimeException in the unlikely case
* that reading information from the environment throws us an
* exception. (Is this really the best thing to do?)</p>
*
* @param myContext an <code>ExpressionContext</code> passed in by the
* extension mechanism. This must be an XPathContext.
* @return a Node as described above.
*/
public static Node checkEnvironment(ExpressionContext myContext)
{
Document factoryDocument;
try
{
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
factoryDocument = db.newDocument();
}
catch(ParserConfigurationException pce)
{
throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(pce);
}
Node resultNode = null;
try
{
// First use reflection to try to load Which, which is a
// better version of EnvironmentCheck
resultNode = checkEnvironmentUsingWhich(myContext, factoryDocument);
if (null != resultNode)
return resultNode;
// If reflection failed, fallback to our internal EnvironmentCheck
EnvironmentCheck envChecker = new EnvironmentCheck();
Hashtable h = envChecker.getEnvironmentHash();
resultNode = factoryDocument.createElement("checkEnvironmentExtension");
envChecker.appendEnvironmentReport(resultNode, factoryDocument, h);
envChecker = null;
}
catch(Exception e)
{
throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(e);
}
return resultNode;
}
/**
* Private worker method to attempt to use org.apache.env.Which.
*
* @param myContext an <code>ExpressionContext</code> passed in by the
* extension mechanism. This must be an XPathContext.
* @param factoryDocument providing createElement services, etc.
* @return a Node with environment info; null if any error
*/
private static Node checkEnvironmentUsingWhich(ExpressionContext myContext,
Document factoryDocument)
{
final String WHICH_CLASSNAME = "org.apache.env.Which";
final String WHICH_METHODNAME = "which";
final Class WHICH_METHOD_ARGS[] = { java.util.Hashtable.class,
java.lang.String.class,
java.lang.String.class };
try
{
// Use reflection to try to find xml-commons utility 'Which'
Class clazz = ObjectFactory.findProviderClass(
WHICH_CLASSNAME, ObjectFactory.findClassLoader(), true);
if (null == clazz)
return null;
// Fully qualify names since this is the only method they're used in
java.lang.reflect.Method method = clazz.getMethod(WHICH_METHODNAME, WHICH_METHOD_ARGS);
Hashtable report = new Hashtable();
// Call the method with our Hashtable, common options, and ignore return value
Object[] methodArgs = { report, "XmlCommons;Xalan;Xerces;Crimson;Ant", "" };
Object returnValue = method.invoke(null, methodArgs);
// Create a parent to hold the report and append hash to it
Node resultNode = factoryDocument.createElement("checkEnvironmentExtension");
com.sun.org.apache.xml.internal.utils.Hashtree2Node.appendHashToNode(report, "whichReport",
resultNode, factoryDocument);
return resultNode;
}
catch (Throwable t)
{
// Simply return null; no need to report error
return null;
}
}
/**
* This class is not loaded until first referenced (see Java Language
* Specification by Gosling/Joy/Steele, section 12.4.1)
*
* The static members are created when this class is first referenced, as a
* lazy initialization not needing checking against null or any
* synchronization.
*
*/
private static class DocumentHolder
{
// Reuse the Document object to reduce memory usage.
private static final Document m_doc;
static
{
try
{
m_doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
}
catch(ParserConfigurationException pce)
{
throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(pce);
}
}
}
}