/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999-2003 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
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* 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.functions;
import java.util.Vector;
import org.apache.xalan.res.XSLMessages;
import org.apache.xpath.Expression;
import org.apache.xpath.ExpressionNode;
import org.apache.xpath.ExpressionOwner;
import org.apache.xpath.ExtensionsProvider;
import org.apache.xpath.XPathContext;
import org.apache.xpath.XPathVisitor;
import org.apache.xpath.objects.XNull;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.res.XPATHErrorResources;
/**
* <meta name="usage" content="advanced"/>
* An object of this class represents an extension call expression. When
* the expression executes, it calls ExtensionsTable#extFunction, and then
* converts the result to the appropriate XObject.
*/
public class FuncExtFunction extends Function
{
/**
* The namespace for the extension function, which should not normally
* be null or empty.
* @serial
*/
String m_namespace;
/**
* The local name of the extension.
* @serial
*/
String m_extensionName;
/**
* Unique method key, which is passed to ExtensionsTable#extFunction in
* order to allow caching of the method.
* @serial
*/
Object m_methodKey;
/**
* Array of static expressions which represent the parameters to the
* function.
* @serial
*/
Vector m_argVec = new Vector();
/**
* 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).
* NEEDSDOC @param globalsSize
*/
public void fixupVariables(java.util.Vector vars, int globalsSize)
{
if (null != m_argVec)
{
int nArgs = m_argVec.size();
for (int i = 0; i < nArgs; i++)
{
Expression arg = (Expression) m_argVec.elementAt(i);
arg.fixupVariables(vars, globalsSize);
}
}
}
/**
* Return the namespace of the extension function.
*
* @return The namespace of the extension function.
*/
public String getNamespace()
{
return m_namespace;
}
/**
* Return the name of the extension function.
*
* @return The name of the extension function.
*/
public String getFunctionName()
{
return m_extensionName;
}
/**
* Return the method key of the extension function.
*
* @return The method key of the extension function.
*/
public Object getMethodKey()
{
return m_methodKey;
}
/**
* Return the nth argument passed to the extension function.
*
* @param n The argument number index.
* @return The Expression object at the given index.
*/
public Expression getArg(int n) {
if (n >= 0 && n < m_argVec.size())
return (Expression) m_argVec.elementAt(n);
else
return null;
}
/**
* Return the number of arguments that were passed
* into this extension function.
*
* @return The number of arguments.
*/
public int getArgCount() {
return m_argVec.size();
}
/**
* Create a new FuncExtFunction based on the qualified name of the extension,
* and a unique method key.
*
* @param namespace The namespace for the extension function, which should
* not normally be null or empty.
* @param extensionName The local name of the extension.
* @param methodKey Unique method key, which is passed to
* ExtensionsTable#extFunction in order to allow caching
* of the method.
*/
public FuncExtFunction(java.lang.String namespace,
java.lang.String extensionName, Object methodKey)
{
//try{throw new Exception("FuncExtFunction() " + namespace + " " + extensionName);} catch (Exception e){e.printStackTrace();}
m_namespace = namespace;
m_extensionName = extensionName;
m_methodKey = methodKey;
}
/**
* Execute the function. The function must return
* a valid object.
* @param xctxt The current execution context.
* @return A valid XObject.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt)
throws javax.xml.transform.TransformerException
{
XObject result;
Vector argVec = new Vector();
int nArgs = m_argVec.size();
for (int i = 0; i < nArgs; i++)
{
Expression arg = (Expression) m_argVec.elementAt(i);
XObject xobj = arg.execute(xctxt);
argVec.addElement(xobj);
}
//dml
ExtensionsProvider extProvider = (ExtensionsProvider)xctxt.getOwnerObject();
Object val = extProvider.extFunction(this, argVec);
if (null != val)
{
result = XObject.create(val, xctxt);
}
else
{
result = new XNull();
}
return result;
}
/**
* Set an argument expression for a function. This method is called by the
* XPath compiler.
*
* @param arg non-null expression that represents the argument.
* @param argNum The argument number index.
*
* @throws WrongNumberArgsException If the argNum parameter is beyond what
* is specified for this function.
*/
public void setArg(Expression arg, int argNum)
throws WrongNumberArgsException
{
m_argVec.addElement(arg);
}
/**
* Check that the number of arguments passed to this function is correct.
*
*
* @param argNum The number of arguments that is being passed to the function.
*
* @throws WrongNumberArgsException
*/
public void checkNumberArgs(int argNum) throws WrongNumberArgsException{}
class ArgExtOwner implements ExpressionOwner
{
Expression m_exp;
ArgExtOwner(Expression exp)
{
m_exp = exp;
}
/**
* @see ExpressionOwner#getExpression()
*/
public Expression getExpression()
{
return m_exp;
}
/**
* @see ExpressionOwner#setExpression(Expression)
*/
public void setExpression(Expression exp)
{
exp.exprSetParent(FuncExtFunction.this);
m_exp = exp;
}
}
/**
* Call the visitors for the function arguments.
*/
public void callArgVisitors(XPathVisitor visitor)
{
for (int i = 0; i < m_argVec.size(); i++)
{
Expression exp = (Expression)m_argVec.elementAt(i);
exp.callVisitors(new ArgExtOwner(exp), visitor);
}
}
/**
* Set the parent node.
* For an extension function, we also need to set the parent
* node for all argument expressions.
*
* @param n The parent node
*/
public void exprSetParent(ExpressionNode n)
{
super.exprSetParent(n);
int nArgs = m_argVec.size();
for (int i = 0; i < nArgs; i++)
{
Expression arg = (Expression) m_argVec.elementAt(i);
arg.exprSetParent(n);
}
}
/**
* Constructs and throws a WrongNumberArgException with the appropriate
* message for this function object. This class supports an arbitrary
* number of arguments, so this method must never be called.
*
* @throws WrongNumberArgsException
*/
protected void reportWrongNumberArgs() throws WrongNumberArgsException {
String fMsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
new Object[]{ "Programmer's assertion: the method FunctionMultiArgs.reportWrongNumberArgs() should never be called." });
throw new RuntimeException(fMsg);
}
}