1/*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5/*
6 * Licensed to the Apache Software Foundation (ASF) under one or more
7 * contributor license agreements.  See the NOTICE file distributed with
8 * this work for additional information regarding copyright ownership.
9 * The ASF licenses this file to You under the Apache License, Version 2.0
10 * (the "License"); you may not use this file except in compliance with
11 * the License.  You may obtain a copy of the License at
12 *
13 *      http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 */
21
22package com.sun.org.apache.xerces.internal.xni;
23
24import java.util.Enumeration;
25
26/**
27 * The Augmentations interface defines a table of additional data that may
28 * be passed along the document pipeline. The information can contain extra
29 * arguments or infoset augmentations, for example PSVI. This additional
30 * information is identified by a String key.
31 * <p>
32 * <strong>Note:</strong>
33 * Methods that receive Augmentations are required to copy the information
34 * if it is to be saved for use beyond the scope of the method.
35 * The Augmentations content is volatile, and maybe modified by any method in
36 * any component in the pipeline. Therefore, methods passed this structure
37 * should not save any reference to the structure.
38 *
39 * @author Elena Litani, IBM
40 */
41
42public interface Augmentations {
43
44
45    /**
46     * Add additional information identified by a key to the Augmentations structure.
47     *
48     * @param key    Identifier, can't be <code>null</code>
49     * @param item   Additional information
50     *
51     * @return the previous value of the specified key in the Augmentations structure,
52     *         or <code>null</code> if it did not have one.
53     */
54    public Object putItem (String key, Object item);
55
56
57    /**
58     * Get information identified by a key from the Augmentations structure
59     *
60     * @param key    Identifier, can't be <code>null</code>
61     *
62     * @return the value to which the key is mapped in the Augmentations structure;
63     *         <code>null</code> if the key is not mapped to any value.
64     */
65    public Object getItem(String key);
66
67
68    /**
69     * Remove additional info from the Augmentations structure
70     *
71     * @param key    Identifier, can't be <code>null</code>
72     * @return the previous value of the specified key in the Augmentations structure,
73     *         or <code>null</code> if it did not have one.
74     */
75    public Object removeItem (String key);
76
77
78    /**
79     * Returns an enumeration of the keys in the Augmentations structure
80     *
81     */
82    public Enumeration keys ();
83
84
85    /**
86     * Remove all objects from the Augmentations structure.
87     */
88    public void removeAllItems ();
89
90}
91