/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//jxpath/src/java/org/apache/commons/jxpath/AbstractFactory.java,v 1.3 2002/04/24 03:29:33 dmitri Exp $
 * $Revision: 1.3 $
 * $Date: 2002/04/24 03:29:33 $
 *
 * ====================================================================
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999-2001 The Apache Software Foundation.  All rights
 * reserved.
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 * 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.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    distribution.
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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.
 *
 * 4. The names "The Jakarta Project", "Commons", 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.
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 * 5. Products derived from this software may not be called "Apache"
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 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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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
 * <http://www.apache.org/>.
 */
package org.apache.commons.jxpath;

/**
 * The {@link JXPathContext#createPath JXPathContext.createPath()} method of JXPathContext can 
 * create missing objects as it traverses an XPath; it utilizes an AbstractFactory for that purpose.
 * Install a factory on JXPathContext by calling {@link JXPathContext#setFactory
 * JXPathContext.setFactory()}.
 * <p>
 * All methods of this class return false.  Override any of them to
 * return true to indicate that the factory has successfully created the described object.
 *
 * @author Dmitri Plotnikov
 * @version $Revision: 1.3 $ $Date: 2002/04/24 03:29:33 $
 */
public abstract class AbstractFactory {

    /**
     * The parameters may describe a collection element or an individual object. It is up
     * to the factory to infer which one it is. If it is a collection, the
     * factory should check if the collection exists.  If not, it should create
     * the collection. Then it should create the index'th element of the collection
     * and return true.
     * <p>
     * 
     * @param context can be used to evaluate other XPaths, get to variables etc.
     * @param pointer describes the location of the node to be created
     * @param parent is the object that will server as a parent of the new object
     * @param name is the name of the child of the parent that needs to be created. 
     *        In the case of DOM may be qualified.
     * @param index is used if the pointer represents a collection element. You may
     *        need to expand or even create the collection to accomodate the new element.
     * 
     * @return true if the object was successfully created
     */
    public boolean createObject(JXPathContext context, Pointer pointer, 
                                Object parent, String name, int index){
        return false;
    }

    /**
     * Create a new object and set it on the specified variable
     * 
     * @param context hosts variable pools. See {@link JXPathContext#getVariables() 
     *        JXPathContext.getVariables()}
     * @param name is the name of the variable without the "$" sign
     * 
     * @return true if the variable was successfully defined
     */
    public boolean declareVariable(JXPathContext context, String name){
        return false;
    }
}