01: /*
02: * Copyright 2002-2006 The Apache Software Foundation.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16:
17: package org.apache.commons.jexl.parser;
18:
19: import org.apache.commons.jexl.JexlContext;
20:
21: /**
22: * x = y, assigns a value to a variable in the context.
23: *
24: * @author Dion Gillard
25: *
26: */
27: public class ASTAssignment extends SimpleNode {
28: /**
29: * Create the node given an id.
30: *
31: * @param id node id.
32: */
33: public ASTAssignment(int id) {
34: super (id);
35: }
36:
37: /**
38: * Create a node with the given parser and id.
39: *
40: * @param p a parser.
41: * @param id node id.
42: */
43: public ASTAssignment(Parser p, int id) {
44: super (p, id);
45: }
46:
47: /** {@inheritDoc} */
48: public Object jjtAccept(ParserVisitor visitor, Object data) {
49: return visitor.visit(this , data);
50: }
51:
52: /** {@inheritDoc} */
53: public Object value(JexlContext context) throws Exception {
54: // left should be the variable (reference) to assign to
55: SimpleNode left = (SimpleNode) jjtGetChild(0);
56: // right should be the expression to evaluate
57: Object right = ((SimpleNode) jjtGetChild(1)).value(context);
58: if (left instanceof ASTReference) {
59: ASTReference reference = (ASTReference) left;
60: left = (SimpleNode) reference.jjtGetChild(0);
61: if (left instanceof ASTIdentifier) {
62: String identifier = ((ASTIdentifier) left)
63: .getIdentifierString();
64: context.getVars().put(identifier, right);
65: }
66: }
67: return right;
68: }
69: }
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