1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.myfaces.view.facelets.el;
20
21 import javax.el.ValueExpression;
22 import javax.el.VariableMapper;
23
24 /**
25 * Composite VariableMapper that attempts to load the ValueExpression from the first VariableMapper, then the second if
26 * <code>null</code>.
27 *
28 * @see javax.el.VariableMapper
29 * @see javax.el.ValueExpression
30 *
31 * @author Jacob Hookom
32 * @version $Id$
33 */
34 public final class CompositeVariableMapper extends VariableMapper
35 {
36
37 private final VariableMapper var0;
38
39 private final VariableMapper var1;
40
41 public CompositeVariableMapper(VariableMapper var0, VariableMapper var1)
42 {
43 this.var0 = var0;
44 this.var1 = var1;
45 }
46
47 /**
48 * @see javax.el.VariableMapper#resolveVariable(java.lang.String)
49 */
50 public ValueExpression resolveVariable(String name)
51 {
52 ValueExpression ve = this.var0.resolveVariable(name);
53 if (ve == null)
54 {
55 return this.var1.resolveVariable(name);
56 }
57 return ve;
58 }
59
60 /**
61 * @see javax.el.VariableMapper#setVariable(java.lang.String, javax.el.ValueExpression)
62 */
63 public ValueExpression setVariable(String name, ValueExpression expression)
64 {
65 return this.var0.setVariable(name, expression);
66 }
67
68 }