    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    }