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.scxml2.env.xpath;
18
19 import org.apache.commons.jxpath.Variables;
20 import org.apache.commons.scxml2.Context;
21 import org.apache.commons.scxml2.env.SimpleContext;
22
23 /**
24 * A {@link Context} implementation for JXPath environments.
25 *
26 */
27 public class XPathContext extends SimpleContext
28 implements Context, Variables {
29
30 /** Serial version UID. */
31 private static final long serialVersionUID = -6803159294612685806L;
32
33 /**
34 * No argument constructor.
35 *
36 */
37 public XPathContext() {
38 super();
39 }
40
41 /**
42 * Constructor for cascading contexts.
43 *
44 * @param parent The parent context. Can be null.
45 */
46 public XPathContext(final Context parent) {
47 super(parent);
48 }
49
50 @Override
51 public boolean isDeclaredVariable(final String varName) {
52 return has(varName);
53 }
54
55 @Override
56 public Object getVariable(final String varName) {
57 return get(varName);
58 }
59
60 @Override
61 public void declareVariable(final String varName, final Object value) {
62 set(varName, value);
63 }
64
65 @Override
66 public void undeclareVariable(final String varName) {
67 if (has(varName)) {
68 Context ctx = this;
69 while (!ctx.hasLocal(varName)) {
70 ctx = ctx.getParent();
71 if (ctx == null) {
72 return;
73 }
74 }
75 ctx.getVars().remove(varName);
76 }
77 }
78 }