1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.betwixt.expression;
18
19 /** <p><code>Expression</code> represents an arbitrary expression on a bean.</p>
20 *
21 * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
22 */
23 public interface Expression {
24
25 /** Evaluates the expression on the bean with the given context
26 * and returns the result
27 *
28 * @param context evaluate against this <code>Context</code>
29 * @return the value of the expression
30 */
31 public Object evaluate(Context context);
32
33
34 /* XXX
35 Is update actually useful?
36 None of the expression implementations i can find do anything when it's called.
37 I suspect that it's been replaced by Updater
38 but i maybe i'm missing something subtle
39 */
40 /** <p>Updates the current bean context with a new String value.
41 * This is typically used when parsing XML and updating a beans value
42 * from XML.<p>
43 *
44 * @param context update this <code>Context</code>
45 * @param newValue the new value for this expression
46 * @deprecated 0.5 use {@link Updater} instead
47 */
48 public void update(Context context, String newValue);
49 }