/*
* $Header: /home/cvspublic/jakarta-commons/jxpath/src/java/org/apache/commons/jxpath/ri/compiler/ExtensionFunction.java,v 1.5 2002/05/08 00:39:59 dmitri Exp $
* $Revision: 1.5 $
* $Date: 2002/05/08 00:39:59 $
*
* ====================================================================
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999-2001 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
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*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
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* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
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* 5. Products derived from this software may not be called "Apache"
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* ====================================================================
*
* 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) 2001, Plotnix, Inc,
* <http://www.plotnix.com/>.
* For more information on the Apache Software Foundation, please see
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*/
package org.apache.commons.jxpath.ri.compiler;
import org.apache.commons.jxpath.Function;
import org.apache.commons.jxpath.JXPathException;
import org.apache.commons.jxpath.ri.QName;
import org.apache.commons.jxpath.ri.EvalContext;
import java.util.Arrays;
/**
* Represents an element of the parse tree representing an extension function call.
*
* @author Dmitri Plotnikov
* @version $Revision: 1.5 $ $Date: 2002/05/08 00:39:59 $
*/
public class ExtensionFunction extends Operation {
private QName functionName;
public ExtensionFunction(QName functionName, Expression args[]){
super(Expression.OP_FUNCTION, args);
this.functionName = functionName;
}
public QName getFunctionName(){
return functionName;
}
/**
* An extension function gets the current context, therefore it MAY be
* context dependent.
*/
public boolean computeContextDependent(){
return true;
}
public String opCodeToString(){
return super.opCodeToString() + ':' + functionName;
}
public Object compute(EvalContext context){
return computeValue(context);
}
public Object computeValue(EvalContext context){
Object[] parameters = null;
if (args != null){
parameters = new Object[args.length];
for (int i = 0; i < args.length; i++){
Object param = args[i].compute(context);
parameters[i] = param;
}
}
Function function = context.getRootContext().getFunction(functionName, parameters);
if (function == null){
throw new JXPathException("No such function: " + functionName +
Arrays.asList(parameters));
}
return function.invoke(context, parameters);
}
}