    1   /*
    2    * Copyright 1999-2004 The Apache Software Foundation
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *     http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  package org.apache.commons.jxpath;
    17
    18  /***
    19   * The  {@link JXPathContext#createPath JXPathContext.createPath()} method of
    20   * JXPathContext can create missing objects as it traverses an XPath; it
    21   * utilizes an AbstractFactory for that purpose. Install a factory on
    22   * JXPathContext by calling {@link JXPathContext#setFactory JXPathContext.
    23   * setFactory()}.
    24   * <p>
    25   * All  methods of this class return false.  Override any of them to return true
    26   * to indicate that the factory has successfully created the described object.
    27   *
    28   * @author Dmitri Plotnikov
    29   * @version $Revision: 1.8 $ $Date: 2004/02/29 14:17:42 $
    30   */
    31  public abstract class AbstractFactory {
    32
    33      /***
    34       * The  parameters may describe a collection element or an individual
    35       * object. It is up to the factory to infer which one it is. If it is a
    36       * collection, the factory should check if the collection exists.  If not,
    37       * it should create the collection. Then it should create the index'th
    38       * element of the collection and return true.
    39       * <p>
    40       *
    41       * @param context can be used to evaluate other XPaths, get to variables
    42       * etc.
    43       * @param pointer describes the location of the node to be created
    44       * @param parent is the object that will server as a parent of the new
    45       * object
    46       * @param name is the name of the child of the parent that needs to be
    47       * created. In the case of DOM may be qualified.
    48       * @param index is used if the pointer represents a collection element. You
    49       * may need to expand or even create the collection to accomodate the new
    50       * element.
    51       *
    52       * @return true if the object was successfully created
    53       */
    54      public boolean createObject(JXPathContext context, Pointer pointer,
    55                                  Object parent, String name, int index)
    56      {
    57          return false;
    58      }
    59
    60      /***
    61       * Declare the specified variable
    62       *
    63       * @param context hosts variable pools. See
    64       * {@link JXPathContext#getVariables() JXPathContext.getVariables()}
    65       * @param name is the name of the variable without the "$" sign
    66       *
    67       * @return true if the variable was successfully defined
    68       */
    69      public boolean declareVariable(JXPathContext context, String name) {
    70          return false;
    71      }
    72  }