- /*
- * 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 1.30 2004/02/17 04:30:02 minchau 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
- {
-
- /** The top of the expression tree.
- * @serial */
- private Expression m_mainExp;
-
- /**
- * 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
- {
- 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);
-
- 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);
- }
-
- /**
- * 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;
- }
-
- /**
- * Install a built-in function.
- * @param name The unqualified name of the function; not currently used.
- * @param funcIndex The index of the function in the table.
- * @param func An Implementation of an XPath Function object.
- * @return the position of the function in the internal index.
- */
- public void installFunction(String name, int funcIndex, Function func)
- {
- FunctionTable.installFunction(func, funcIndex);
- }
-
- /**
- * 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;
- }