/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xpath.operations;
import org.apache.xml.utils.QName;
import org.apache.xpath.Expression;
import org.apache.xpath.XPath;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XNodeSet;
import org.w3c.dom.Node;
import org.apache.xpath.res.XPATHErrorResources;
/**
* The variable reference expression executer.
*/
public class Variable extends Expression
{
/** Tell if fixupVariables was called.
* @serial */
private boolean m_fixUpWasCalled = false;
/** The qualified name of the variable.
* @serial */
protected QName m_qname;
/**
* The index of the variable, which is either an absolute index to a
* global, or, if higher than the globals area, must be adjusted by adding
* the offset to the current stack frame.
*/
protected int m_index;
protected boolean m_isGlobal = false;
/**
* 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_fixUpWasCalled = true;
int sz = vars.size();
for (int i = vars.size()-1; i >= 0; i--)
{
QName qn = (QName)vars.elementAt(i);
// System.out.println("qn: "+qn);
if(qn.equals(m_qname))
{
if(i < globalsSize)
{
m_isGlobal = true;
m_index = i;
}
else
{
m_index = i-globalsSize;
}
return;
}
}
throw new RuntimeException("Could not find variable with the name of "
+m_qname.toString()+"!");
}
/**
* Set the qualified name of the variable.
*
* @param qname Must be a non-null reference to a qualified name.
*/
public void setQName(QName qname)
{
m_qname = qname;
}
/**
* Dereference the variable, and return the reference value. Note that lazy
* evaluation will occur. If a variable within scope is not found, a warning
* will be sent to the error listener, and an empty nodeset will be returned.
*
*
* @param xctxt The runtime execution context.
*
* @return The evaluated variable, or an empty nodeset if not found.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
{
// Is the variable fetched always the same?
// XObject result = xctxt.getVariable(m_qname);
if(m_fixUpWasCalled)
{
XObject result;
if(m_isGlobal)
result = xctxt.getVarStack().getGlobalVariable(xctxt, m_index);
else
result = xctxt.getVarStack().getLocalVariable(xctxt, m_index);
if (null == result)
{
// This should now never happen...
warn(xctxt, XPATHErrorResources.WG_ILLEGAL_VARIABLE_REFERENCE,
new Object[]{ m_qname.getLocalPart() }); //"VariableReference given for variable out "+
// (new RuntimeException()).printStackTrace();
// error(xctxt, XPATHErrorResources.ER_COULDNOT_GET_VAR_NAMED,
// new Object[]{ m_qname.getLocalPart() }); //"Could not get variable named "+varName);
result = new XNodeSet(xctxt.getDTMManager());
}
return result;
}
else
{
// Hack city... big time. This is needed to evaluate xpaths from extensions,
// pending some bright light going off in my head. Some sort of callback?
synchronized(this)
{
org.apache.xml.utils.PrefixResolver prefixResolver = xctxt.getNamespaceContext();
// Get the current ElemTemplateElement, which must be pushed in as the
// prefix resolver, and then walk backwards in document order, searching
// for an xsl:param element or xsl:variable element that matches our
// qname. For this to work really correctly, the stylesheet element
// should be immediatly resolve to the root stylesheet, and the operation
// performed on it's list of global variables. But that will have to wait
// for another day, or someone else can do it, or I will come up with a
// better solution to this whole damned hack.
if(prefixResolver instanceof org.apache.xalan.templates.ElemTemplateElement)
{
org.apache.xalan.templates.ElemTemplateElement prev =
(org.apache.xalan.templates.ElemTemplateElement)prefixResolver;
while(null != prev)
{
org.apache.xalan.templates.ElemTemplateElement savedprev = prev;
while(null != (prev = prev.getPreviousSiblingElem()))
{
if(prev instanceof org.apache.xalan.templates.ElemVariable)
{
org.apache.xalan.templates.ElemVariable vvar =
(org.apache.xalan.templates.ElemVariable)prev;
if(vvar.getName().equals(m_qname))
{
m_index = vvar.getIndex();
m_isGlobal = vvar.getIsTopLevel();
m_fixUpWasCalled = true;
return execute(xctxt);
}
}
}
prev = savedprev.getParentElem();
}
}
}
throw new javax.xml.transform.TransformerException("Variable not resolavable: "+m_qname);
}
}
}