/*
* 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: XPath.java,v 1.2.4.1 2005/09/15 01:41:57 jeffsuttor Exp $
*/
package com.sun.org.apache.xpath.internal;
import java.io.Serializable;
import javax.xml.transform.ErrorListener;
import javax.xml.transform.SourceLocator;
import javax.xml.transform.TransformerException;
import com.sun.org.apache.xalan.internal.res.XSLMessages;
import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.utils.PrefixResolver;
import com.sun.org.apache.xml.internal.utils.SAXSourceLocator;
import com.sun.org.apache.xpath.internal.compiler.Compiler;
import com.sun.org.apache.xpath.internal.compiler.FunctionTable;
import com.sun.org.apache.xpath.internal.compiler.XPathParser;
import com.sun.org.apache.xpath.internal.functions.Function;
import com.sun.org.apache.xpath.internal.objects.XObject;
import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;
/**
* The XPath class wraps an expression object and provides general services
* for execution of that expression.
* @xsl.usage advanced
*/
public class XPath implements Serializable, ExpressionOwner
{
static final long serialVersionUID = 3976493477939110553L;
/** The top of the expression tree.
* @serial */
private Expression m_mainExp;
/**
* The function table for xpath build-in functions
*/
private transient FunctionTable m_funcTable = null;
/**
* initial the function table
*/
private void initFunctionTable(){
m_funcTable = new FunctionTable();
}
/**
* Get the raw Expression object that this class wraps.
*
*
* @return the raw Expression object, which should not normally be null.
*/
public Expression getExpression()
{
return m_mainExp;
}
/**
* This function is used to fixup variables from QNames to stack frame
* indexes at stylesheet build time.
* @param vars List of QNames that correspond to variables. This list
* should be searched backwards for the first qualified name that
* corresponds to the variable reference qname. The position of the
* QName in the vector from the start of the vector will be its position
* in the stack frame (but variables above the globalsTop value will need
* to be offset to the current stack frame).
*/
public void fixupVariables(java.util.Vector vars, int globalsSize)
{
m_mainExp.fixupVariables(vars, globalsSize);
}
/**
* Set the raw expression object for this object.
*
*
* @param exp the raw Expression object, which should not normally be null.
*/
public void setExpression(Expression exp)
{
if(null != m_mainExp)
exp.exprSetParent(m_mainExp.exprGetParent()); // a bit bogus
m_mainExp = exp;
}
/**
* Get the SourceLocator on the expression object.
*
*
* @return the SourceLocator on the expression object, which may be null.
*/
public SourceLocator getLocator()
{
return m_mainExp;
}
// /**
// * Set the SourceLocator on the expression object.
// *
// *
// * @param l the SourceLocator on the expression object, which may be null.
// */
// public void setLocator(SourceLocator l)
// {
// // Note potential hazards -- l may not be serializable, or may be changed
// // after being assigned here.
// m_mainExp.setSourceLocator(l);
// }
/** The pattern string, mainly kept around for diagnostic purposes.
* @serial */
String m_patternString;
/**
* Return the XPath string associated with this object.
*
*
* @return the XPath string associated with this object.
*/
public String getPatternString()
{
return m_patternString;
}
/** Represents a select type expression. */
public static final int SELECT = 0;
/** Represents a match type expression. */
public static final int MATCH = 1;
/**
* Construct an XPath object.
*
* (Needs review -sc) This method initializes an XPathParser/
* Compiler and compiles the expression.
* @param exprString The XPath expression.
* @param locator The location of the expression, may be null.
* @param prefixResolver A prefix resolver to use to resolve prefixes to
* namespace URIs.
* @param type one of {@link #SELECT} or {@link #MATCH}.
* @param errorListener The error listener, or null if default should be used.
*
* @throws javax.xml.transform.TransformerException if syntax or other error.
*/
public XPath(
String exprString, SourceLocator locator, PrefixResolver prefixResolver, int type,
ErrorListener errorListener)
throws javax.xml.transform.TransformerException
{
initFunctionTable();
if(null == errorListener)
errorListener = new com.sun.org.apache.xml.internal.utils.DefaultErrorHandler();
m_patternString = exprString;
XPathParser parser = new XPathParser(errorListener, locator);
Compiler compiler = new Compiler(errorListener, locator, m_funcTable);
if (SELECT == type)
parser.initXPath(compiler, exprString, prefixResolver);
else if (MATCH == type)
parser.initMatchPattern(compiler, exprString, prefixResolver);
else
throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_CANNOT_DEAL_XPATH_TYPE, new Object[]{Integer.toString(type)})); //"Can not deal with XPath type: " + type);
// System.out.println("----------------");
Expression expr = compiler.compile(0);
// System.out.println("expr: "+expr);
this.setExpression(expr);
if((null != locator) && locator instanceof ExpressionNode)
{
expr.exprSetParent((ExpressionNode)locator);
}
}
/**
* Construct an XPath object.
*
* (Needs review -sc) This method initializes an XPathParser/
* Compiler and compiles the expression.
* @param exprString The XPath expression.
* @param locator The location of the expression, may be null.
* @param prefixResolver A prefix resolver to use to resolve prefixes to
* namespace URIs.
* @param type one of {@link #SELECT} or {@link #MATCH}.
* @param errorListener The error listener, or null if default should be used.
*
* @throws javax.xml.transform.TransformerException if syntax or other error.
*/
public XPath(
String exprString, SourceLocator locator,
PrefixResolver prefixResolver, int type,
ErrorListener errorListener, FunctionTable aTable)
throws javax.xml.transform.TransformerException
{
m_funcTable = aTable;
if(null == errorListener)
errorListener = new com.sun.org.apache.xml.internal.utils.DefaultErrorHandler();
m_patternString = exprString;
XPathParser parser = new XPathParser(errorListener, locator);
Compiler compiler = new Compiler(errorListener, locator, m_funcTable);
if (SELECT == type)
parser.initXPath(compiler, exprString, prefixResolver);
else if (MATCH == type)
parser.initMatchPattern(compiler, exprString, prefixResolver);
else
throw new RuntimeException(XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_CANNOT_DEAL_XPATH_TYPE,
new Object[]{Integer.toString(type)}));
//"Can not deal with XPath type: " + type);
// System.out.println("----------------");
Expression expr = compiler.compile(0);
// System.out.println("expr: "+expr);
this.setExpression(expr);
if((null != locator) && locator instanceof ExpressionNode)
{
expr.exprSetParent((ExpressionNode)locator);
}
}
/**
* Construct an XPath object.
*
* (Needs review -sc) This method initializes an XPathParser/
* Compiler and compiles the expression.
* @param exprString The XPath expression.
* @param locator The location of the expression, may be null.
* @param prefixResolver A prefix resolver to use to resolve prefixes to
* namespace URIs.
* @param type one of {@link #SELECT} or {@link #MATCH}.
*
* @throws javax.xml.transform.TransformerException if syntax or other error.
*/
public XPath(
String exprString, SourceLocator locator, PrefixResolver prefixResolver, int type)
throws javax.xml.transform.TransformerException
{
this(exprString, locator, prefixResolver, type, null);
}
/**
* Construct an XPath object.
*
* @param expr The Expression object.
*
* @throws javax.xml.transform.TransformerException if syntax or other error.
*/
public XPath(Expression expr)
{
this.setExpression(expr);
initFunctionTable();
}
/**
* Given an expression and a context, evaluate the XPath
* and return the result.
*
* @param xctxt The execution context.
* @param contextNode The node that "." expresses.
* @param namespaceContext The context in which namespaces in the
* XPath are supposed to be expanded.
*
* @return The result of the XPath or null if callbacks are used.
* @throws TransformerException thrown if
* the error condition is severe enough to halt processing.
*
* @throws javax.xml.transform.TransformerException
* @xsl.usage experimental
*/
public XObject execute(
XPathContext xctxt, org.w3c.dom.Node contextNode,
PrefixResolver namespaceContext)
throws javax.xml.transform.TransformerException
{
return execute(
xctxt, xctxt.getDTMHandleFromNode(contextNode),
namespaceContext);
}
/**
* Given an expression and a context, evaluate the XPath
* and return the result.
*
* @param xctxt The execution context.
* @param contextNode The node that "." expresses.
* @param namespaceContext The context in which namespaces in the
* XPath are supposed to be expanded.
*
* @throws TransformerException thrown if the active ProblemListener decides
* the error condition is severe enough to halt processing.
*
* @throws javax.xml.transform.TransformerException
* @xsl.usage experimental
*/
public XObject execute(
XPathContext xctxt, int contextNode, PrefixResolver namespaceContext)
throws javax.xml.transform.TransformerException
{
xctxt.pushNamespaceContext(namespaceContext);
xctxt.pushCurrentNodeAndExpression(contextNode, contextNode);
XObject xobj = null;
try
{
xobj = m_mainExp.execute(xctxt);
}
catch (TransformerException te)
{
te.setLocator(this.getLocator());
ErrorListener el = xctxt.getErrorListener();
if(null != el) // defensive, should never happen.
{
el.error(te);
}
else
throw te;
}
catch (Exception e)
{
while (e instanceof com.sun.org.apache.xml.internal.utils.WrappedRuntimeException)
{
e = ((com.sun.org.apache.xml.internal.utils.WrappedRuntimeException) e).getException();
}
// e.printStackTrace();
String msg = e.getMessage();
if (msg == null || msg.length() == 0) {
msg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_XPATH_ERROR, null);
}
TransformerException te = new TransformerException(msg,
getLocator(), e);
ErrorListener el = xctxt.getErrorListener();
// te.printStackTrace();
if(null != el) // defensive, should never happen.
{
el.fatalError(te);
}
else
throw te;
}
finally
{
xctxt.popNamespaceContext();
xctxt.popCurrentNodeAndExpression();
}
return xobj;
}
/**
* Given an expression and a context, evaluate the XPath
* and return the result.
*
* @param xctxt The execution context.
* @param contextNode The node that "." expresses.
* @param namespaceContext The context in which namespaces in the
* XPath are supposed to be expanded.
*
* @throws TransformerException thrown if the active ProblemListener decides
* the error condition is severe enough to halt processing.
*
* @throws javax.xml.transform.TransformerException
* @xsl.usage experimental
*/
public boolean bool(
XPathContext xctxt, int contextNode, PrefixResolver namespaceContext)
throws javax.xml.transform.TransformerException
{
xctxt.pushNamespaceContext(namespaceContext);
xctxt.pushCurrentNodeAndExpression(contextNode, contextNode);
try
{
return m_mainExp.bool(xctxt);
}
catch (TransformerException te)
{
te.setLocator(this.getLocator());
ErrorListener el = xctxt.getErrorListener();
if(null != el) // defensive, should never happen.
{
el.error(te);
}
else
throw te;
}
catch (Exception e)
{
while (e instanceof com.sun.org.apache.xml.internal.utils.WrappedRuntimeException)
{
e = ((com.sun.org.apache.xml.internal.utils.WrappedRuntimeException) e).getException();
}
// e.printStackTrace();
String msg = e.getMessage();
if (msg == null || msg.length() == 0) {
msg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_XPATH_ERROR, null);
}
TransformerException te = new TransformerException(msg,
getLocator(), e);
ErrorListener el = xctxt.getErrorListener();
// te.printStackTrace();
if(null != el) // defensive, should never happen.
{
el.fatalError(te);
}
else
throw te;
}
finally
{
xctxt.popNamespaceContext();
xctxt.popCurrentNodeAndExpression();
}
return false;
}
/** Set to true to get diagnostic messages about the result of
* match pattern testing. */
private static final boolean DEBUG_MATCHES = false;
/**
* Get the match score of the given node.
*
* @param xctxt XPath runtime context.
* @param context The current source tree context node.
*
* @return score, one of {@link #MATCH_SCORE_NODETEST},
* {@link #MATCH_SCORE_NONE}, {@link #MATCH_SCORE_OTHER},
* or {@link #MATCH_SCORE_QNAME}.
*
* @throws javax.xml.transform.TransformerException
*/
public double getMatchScore(XPathContext xctxt, int context)
throws javax.xml.transform.TransformerException
{
xctxt.pushCurrentNode(context);
xctxt.pushCurrentExpressionNode(context);
try
{
XObject score = m_mainExp.execute(xctxt);
if (DEBUG_MATCHES)
{
DTM dtm = xctxt.getDTM(context);
System.out.println("score: " + score.num() + " for "
+ dtm.getNodeName(context) + " for xpath "
+ this.getPatternString());
}
return score.num();
}
finally
{
xctxt.popCurrentNode();
xctxt.popCurrentExpressionNode();
}
// return XPath.MATCH_SCORE_NONE;
}
/**
* Warn the user of an problem.
*
* @param xctxt The XPath runtime context.
* @param sourceNode Not used.
* @param msg An error msgkey that corresponds to one of the constants found
* in {@link com.sun.org.apache.xpath.internal.res.XPATHErrorResources}, which is
* a key for a format string.
* @param args An array of arguments represented in the format string, which
* may be null.
*
* @throws TransformerException if the current ErrorListoner determines to
* throw an exception.
*/
public void warn(
XPathContext xctxt, int sourceNode, String msg, Object[] args)
throws javax.xml.transform.TransformerException
{
String fmsg = XSLMessages.createXPATHWarning(msg, args);
ErrorListener ehandler = xctxt.getErrorListener();
if (null != ehandler)
{
// TO DO: Need to get stylesheet Locator from here.
ehandler.warning(new TransformerException(fmsg, (SAXSourceLocator)xctxt.getSAXLocator()));
}
}
/**
* Tell the user of an assertion error, and probably throw an
* exception.
*
* @param b If false, a runtime exception will be thrown.
* @param msg The assertion message, which should be informative.
*
* @throws RuntimeException if the b argument is false.
*/
public void assertion(boolean b, String msg)
{
if (!b)
{
String fMsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
new Object[]{ msg });
throw new RuntimeException(fMsg);
}
}
/**
* Tell the user of an error, and probably throw an
* exception.
*
* @param xctxt The XPath runtime context.
* @param sourceNode Not used.
* @param msg An error msgkey that corresponds to one of the constants found
* in {@link com.sun.org.apache.xpath.internal.res.XPATHErrorResources}, which is
* a key for a format string.
* @param args An array of arguments represented in the format string, which
* may be null.
*
* @throws TransformerException if the current ErrorListoner determines to
* throw an exception.
*/
public void error(
XPathContext xctxt, int sourceNode, String msg, Object[] args)
throws javax.xml.transform.TransformerException
{
String fmsg = XSLMessages.createXPATHMessage(msg, args);
ErrorListener ehandler = xctxt.getErrorListener();
if (null != ehandler)
{
ehandler.fatalError(new TransformerException(fmsg,
(SAXSourceLocator)xctxt.getSAXLocator()));
}
else
{
SourceLocator slocator = xctxt.getSAXLocator();
System.out.println(fmsg + "; file " + slocator.getSystemId()
+ "; line " + slocator.getLineNumber() + "; column "
+ slocator.getColumnNumber());
}
}
/**
* This will traverse the heararchy, calling the visitor for
* each member. If the called visitor method returns
* false, the subtree should not be called.
*
* @param owner The owner of the visitor, where that path may be
* rewritten if needed.
* @param visitor The visitor whose appropriate method will be called.
*/
public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
{
m_mainExp.callVisitors(this, visitor);
}
/**
* The match score if no match is made.
* @xsl.usage advanced
*/
public static final double MATCH_SCORE_NONE = Double.NEGATIVE_INFINITY;
/**
* The match score if the pattern has the form
* of a QName optionally preceded by an @ character.
* @xsl.usage advanced
*/
public static final double MATCH_SCORE_QNAME = 0.0;
/**
* The match score if the pattern pattern has the form NCName:*.
* @xsl.usage advanced
*/
public static final double MATCH_SCORE_NSWILD = -0.25;
/**
* The match score if the pattern consists of just a NodeTest.
* @xsl.usage advanced
*/
public static final double MATCH_SCORE_NODETEST = -0.5;
/**
* The match score if the pattern consists of something
* other than just a NodeTest or just a qname.
* @xsl.usage advanced
*/
public static final double MATCH_SCORE_OTHER = 0.5;
}