01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * 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.cocoon.components.variables;
18:
19: import org.apache.cocoon.sitemap.PatternException;
20:
21: /**
22: * No-op implementation of {@link VariableResolver} for constant expressions
23: *
24: * @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
25: *
26: * @version CVS $Id: NOPVariableResolver.java 433543 2006-08-22 06:22:54Z crossley $
27: */
28: public class NOPVariableResolver implements VariableResolver {
29:
30: protected String expression;
31:
32: public NOPVariableResolver(String expression) {
33: this .expression = this .unescape(expression);
34: }
35:
36: /**
37: * Unescape an expression that doesn't need to be resolved, but may contain
38: * escaped '{' characters.
39: *
40: * @param expression the expression to unescape.
41: * @return the unescaped result, or <code>expression</code> if unescaping isn't necessary.
42: */
43: protected String unescape(String expression) {
44: // Does it need escaping ?
45: if (expression == null || expression.indexOf("\\{") == -1) {
46: return expression;
47: }
48:
49: StringBuffer buf = new StringBuffer();
50: for (int i = 0; i < expression.length(); i++) {
51: char ch = expression.charAt(i);
52: if (ch != '\\' || i >= (expression.length() - 1)
53: || expression.charAt(i + 1) != '{') {
54: buf.append(ch);
55: }
56: }
57:
58: return buf.toString();
59: }
60:
61: /* (non-Javadoc)
62: * @see org.apache.cocoon.components.variables.VariableResolver#resolve()
63: */
64: public String resolve() throws PatternException {
65: return this.expression;
66: }
67:
68: }
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