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
18 package org.apache.commons.jxpath.ri.compiler;
19
20 import org.apache.commons.jxpath.ri.EvalContext;
21 import org.apache.commons.jxpath.ri.QName;
22
23 /**
24 * An element of the compile tree holding a variable reference.
25 */
26 public class VariableReference extends Expression {
27
28 private final QName varName;
29
30 /**
31 * Constructs a new VariableReference.
32 *
33 * @param varName variable name
34 */
35 public VariableReference(final QName varName) {
36 this.varName = varName;
37 }
38
39 @Override
40 public Object compute(final EvalContext context) {
41 return computeValue(context);
42 }
43
44 @Override
45 public boolean computeContextDependent() {
46 return false;
47 }
48
49 /**
50 * Returns the value of the variable.
51 *
52 * @param context EvalContext against which to compute the variable's value.
53 * @return Object
54 */
55 @Override
56 public Object computeValue(final EvalContext context) {
57 return context.getRootContext().getVariableContext(varName);
58 }
59
60 /**
61 * Gets the variable name.
62 *
63 * @return QName
64 */
65 public QName getVariableName() {
66 return varName;
67 }
68
69 @Override
70 public boolean isContextDependent() {
71 return false;
72 }
73
74 @Override
75 public String toString() {
76 return "$" + varName;
77 }
78 }