/*
* 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.xalan.templates;
import org.apache.xpath.XPath;
import org.apache.xpath.XPathContext;
import org.apache.xpath.VariableStack;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XRTreeFrag;
import org.apache.xpath.objects.XString;
import org.apache.xalan.transformer.TransformerImpl;
import org.apache.xalan.res.XSLMessages;
import org.apache.xalan.res.XSLTErrorResources;
//import org.w3c.dom.DocumentFragment;
//import org.w3c.dom.Node;
import org.apache.xml.dtm.DTM;
/**
* An instance of this class holds unto a variable until
* it is executed. It is used at this time for global
* variables which must (we think) forward reference.
*/
public class XUnresolvedVariable extends XObject
{
/** The node context for execution. */
transient private int m_context;
/** The transformer context for execution. */
transient private TransformerImpl m_transformer;
/** An index to the point in the variable stack where we should
* begin variable searches for evaluation of expressions.
* This is -1 if m_isTopLevel is false.
**/
transient private int m_varStackPos = -1;
/** An index into the variable stack where the variable context
* ends, i.e. at the point we should terminate the search.
**/
transient private int m_varStackContext;
/** true if this variable or parameter is a global.
* @serial */
private boolean m_isGlobal;
/** true if this variable or parameter is not currently being evaluated. */
transient private boolean m_doneEval = true;
/**
* Create an XUnresolvedVariable, that may be executed at a later time.
* This is primarily used so that forward referencing works with
* global variables. An XUnresolvedVariable is initially pushed
* into the global variable stack, and then replaced with the real
* thing when it is accessed.
*
* @param obj Must be a non-null reference to an ElemVariable.
* @param sourceNode The node context for execution.
* @param transformer The transformer execution context.
* @param varStackPos An index to the point in the variable stack where we should
* begin variable searches for evaluation of expressions.
* @param varStackContext An index into the variable stack where the variable context
* ends, i.e. at the point we should terminate the search.
* @param isGlobal true if this is a global variable.
*/
public XUnresolvedVariable(ElemVariable obj, int sourceNode,
TransformerImpl transformer,
int varStackPos, int varStackContext,
boolean isGlobal)
{
super(obj);
m_context = sourceNode;
m_transformer = transformer;
// For globals, this value will have to be updated once we
// have determined how many global variables have been pushed.
m_varStackPos = varStackPos;
// For globals, this should zero.
m_varStackContext = varStackContext;
m_isGlobal = isGlobal;
}
/**
* For support of literal objects in xpaths.
*
* @param xctxt The XPath execution context.
*
* @return This object.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
{
if (!m_doneEval)
{
this.m_transformer.getMsgMgr().error
(xctxt.getSAXLocator(), XSLTErrorResources.ER_REFERENCING_ITSELF,
new Object[]{((ElemVariable)this.object()).getName().getLocalName()});
}
VariableStack vars = xctxt.getVarStack();
// These three statements need to be combined into one operation.
int currentFrame = vars.getStackFrame();
//// vars.setStackFrame(m_varStackPos);
ElemVariable velem = (ElemVariable)m_obj;
try
{
m_doneEval = false;
if(-1 != velem.m_frameSize)
vars.link(velem.m_frameSize);
XObject var = velem.getValue(m_transformer, m_context);
m_doneEval = true;
return var;
}
finally
{
// These two statements need to be combined into one operation.
// vars.setStackFrame(currentFrame);
if(-1 != velem.m_frameSize)
vars.unlink(currentFrame);
}
}
/**
* Set an index to the point in the variable stack where we should
* begin variable searches for evaluation of expressions.
* This is -1 if m_isTopLevel is false.
*
* @param top A valid value that specifies where in the variable
* stack the search should begin.
*/
public void setVarStackPos(int top)
{
m_varStackPos = top;
}
/**
* Set an index into the variable stack where the variable context
* ends, i.e. at the point we should terminate the search.
*
* @param The point at which the search should terminate, normally
* zero for global variables.
*/
public void setVarStackContext(int bottom)
{
m_varStackContext = bottom;
}
/**
* Tell what kind of class this is.
*
* @return CLASS_UNRESOLVEDVARIABLE
*/
public int getType()
{
return CLASS_UNRESOLVEDVARIABLE;
}
/**
* Given a request type, return the equivalent string.
* For diagnostic purposes.
*
* @return An informational string.
*/
public String getTypeString()
{
return "XUnresolvedVariable (" + object().getClass().getName() + ")";
}
}