/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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 */

package org.apache.xerces.xni;

import java.util.Enumeration;

The Augmentations interface defines a table of additional data that may
be passed along the document pipeline. The information can contain extra
arguments or infoset augmentations, for example PSVI. This additional
information is identified by a String key.

Note:
Methods that receive Augmentations are required to copy the information
if it is to be saved for use beyond the scope of the method.
The Augmentations content is volatile, and maybe modified by any method in
any component in the pipeline. Therefore, methods passed this structure
should not save any reference to the structure.
Author:
Elena Litani, IBM
Version:
$Id: Augmentations.java 447247 2006-09-18 05:23:52Z mrglavas $/**
 * The Augmentations interface defines a table of additional data that may
 * be passed along the document pipeline. The information can contain extra
 * arguments or infoset augmentations, for example PSVI. This additional
 * information is identified by a String key.
 * <p>
 * <strong>Note:</strong>
 * Methods that receive Augmentations are required to copy the information
 * if it is to be saved for use beyond the scope of the method.
 * The Augmentations content is volatile, and maybe modified by any method in
 * any component in the pipeline. Therefore, methods passed this structure
 * should not save any reference to the structure.
 * 
 * @author Elena Litani, IBM
 * @version $Id: Augmentations.java 447247 2006-09-18 05:23:52Z mrglavas $
 */

public interface Augmentations {
    
    
    
Add additional information identified by a key to the Augmentations structure.
Params:
key –    Identifier, can't be null
item –   Additional information
Returns:
the previous value of the specified key in the Augmentations structure,
        or null if it did not have one./**
     * Add additional information identified by a key to the Augmentations structure.
     * 
     * @param key    Identifier, can't be <code>null</code>
     * @param item   Additional information
     *
     * @return the previous value of the specified key in the Augmentations structure,
     *         or <code>null</code> if it did not have one.
     */
    public Object putItem (String key, Object item);


    
Get information identified by a key from the Augmentations structure
Params:
key –    Identifier, can't be null
Returns:
the value to which the key is mapped in the Augmentations structure;
        null if the key is not mapped to any value./**
     * Get information identified by a key from the Augmentations structure
     * 
     * @param key    Identifier, can't be <code>null</code>
     *
     * @return the value to which the key is mapped in the Augmentations structure;
     *         <code>null</code> if the key is not mapped to any value.
     */
    public Object getItem(String key);
    
    
    
Remove additional info from the Augmentations structure
Params:
key –    Identifier, can't be null
Returns:
the previous value of the specified key in the Augmentations structure,
        or null if it did not have one./**
     * Remove additional info from the Augmentations structure
     * 
     * @param key    Identifier, can't be <code>null</code>
     * @return the previous value of the specified key in the Augmentations structure,
     *         or <code>null</code> if it did not have one.
     */
    public Object removeItem (String key);

    
    
Returns an enumeration of the keys in the Augmentations structure
/**
     * Returns an enumeration of the keys in the Augmentations structure
     *
     */
    public Enumeration keys ();


    
Remove all objects from the Augmentations structure.
/**
     * Remove all objects from the Augmentations structure.
     */
    public void removeAllItems ();

}