Source Code Cross Referenced for SimpleSelector.java in  » Content-Management-System » apache-lenya-2.0 » org » apache » cocoon » selection » Java Source Code / Java DocumentationJava Source Code and Java Documentation

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.selection;
18:
19:        import java.util.Map;
20:
21:        import org.apache.avalon.framework.parameters.Parameters;
22:
23:        /**
24:         * A very simple selector that operates on string literals, useful especially 
25:         * in conjunction with input modules. Usage example:
26:         * <pre>
27:         *    &lt;map:selector name="simple" src="org.apache.cocoon.selection.SimpleSelector"/&gt;
28:         * 
29:         *    &lt;map:select type="simple"&gt;
30:         *       &lt;map:parameter name="value" value="{request:method}"/&gt;
31:         *       &lt;map:when test="GET"&gt;
32:         *           ...
33:         *       &lt;/map:when&gt;
34:         *       &lt;map:when test="POST"&gt;
35:         *           ...
36:         *       &lt;/map:when&gt;
37:         *       &lt;map:when test="PUT"&gt;
38:         *           ...
39:         *       &lt;/map:when&gt;
40:         *       &lt;map:otherwise&gt;
41:         *           ...
42:         *       &lt;/map:otherwise&gt;
43:         *    &lt;/map:select&gt;
44:         * </pre>
45:         * 
46:         * @author <a href="mailto:haul@apache.org">Christian Haul</a>
47:         * @version CVS $Id: SimpleSelector.java 433543 2006-08-22 06:22:54Z crossley $
48:         * @since 2.1
49:         */
50:        public class SimpleSelector extends AbstractSwitchSelector {
51:
52:            public Object getSelectorContext(Map objectModel,
53:                    Parameters parameters) {
54:                return parameters.getParameter("value", "");
55:            }
56:
57:            public boolean select(String expression, Object selectorContext) {
58:                if (selectorContext == null) {
59:                    if (getLogger().isWarnEnabled())
60:                        getLogger().warn("Value not set -- failing.");
61:                    return false;
62:                }
63:
64:                return selectorContext.equals(expression);
65:            }
66:
67:        }