001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.jxpath;
018    
019    /**
020     * The  {@link JXPathContext#createPath JXPathContext.createPath()} method of
021     * JXPathContext can create missing objects as it traverses an XPath; it
022     * utilizes an AbstractFactory for that purpose. Install a factory on
023     * JXPathContext by calling {@link JXPathContext#setFactory JXPathContext.
024     * setFactory()}.
025     * <p>
026     * All  methods of this class return false.  Override any of them to return true
027     * to indicate that the factory has successfully created the described object.
028     *
029     * @author Dmitri Plotnikov
030     * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
031     */
032    public abstract class AbstractFactory {
033    
034        /**
035         * The  parameters may describe a collection element or an individual
036         * object. It is up to the factory to infer which one it is. If it is a
037         * collection, the factory should check if the collection exists.  If not,
038         * it should create the collection. Then it should create the index'th
039         * element of the collection and return true.
040         * <p>
041         *
042         * @param context can be used to evaluate other XPaths, get to variables
043         * etc.
044         * @param pointer describes the location of the node to be created
045         * @param parent is the object that will serve as a parent of the new
046         * object
047         * @param name is the name of the child of the parent that needs to be
048         * created. In the case of DOM may be qualified.
049         * @param index is used if the pointer represents a collection element. You
050         * may need to expand or even create the collection to accommodate the new
051         * element.
052         *
053         * @return true if the object was successfully created
054         */
055        public boolean createObject(JXPathContext context, Pointer pointer,
056                                    Object parent, String name, int index) {
057            return false;
058        }
059    
060        /**
061         * Declare the specified variable
062         *
063         * @param context hosts variable pools. See
064         * {@link JXPathContext#getVariables() JXPathContext.getVariables()}
065         * @param name is the name of the variable without the "$" sign
066         *
067         * @return true if the variable was successfully defined
068         */
069        public boolean declareVariable(JXPathContext context, String name) {
070            return false;
071        }
072    }