Source Code Cross Referenced for If.java in  » Web-Framework » struts-2.0.11 » org » apache » struts2 » components » Java Source Code / Java DocumentationJava Source Code and Java Documentation

01:        /*
02:         * $Id: If.java 497654 2007-01-19 00:21:57Z rgielen $
03:         *
04:         * Licensed to the Apache Software Foundation (ASF) under one
05:         * or more contributor license agreements.  See the NOTICE file
06:         * distributed with this work for additional information
07:         * regarding copyright ownership.  The ASF licenses this file
08:         * to you under the Apache License, Version 2.0 (the
09:         * "License"); you may not use this file except in compliance
10:         * with the License.  You may obtain a copy of the License at
11:         *
12:         *  http://www.apache.org/licenses/LICENSE-2.0
13:         *
14:         * Unless required by applicable law or agreed to in writing,
15:         * software distributed under the License is distributed on an
16:         * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17:         * KIND, either express or implied.  See the License for the
18:         * specific language governing permissions and limitations
19:         * under the License.
20:         */
21:        package org.apache.struts2.components;
22:
23:        import java.io.Writer;
24:
25:        import org.apache.struts2.views.annotations.StrutsTag;
26:        import org.apache.struts2.views.annotations.StrutsTagAttribute;
27:
28:        import com.opensymphony.xwork2.util.ValueStack;
29:
30:        /**
31:         * <!-- START SNIPPET: javadoc -->
32:         *
33:         * <p>Perform basic condition flow. 'If' tag could be used by itself or
34:         * with 'Else If' Tag and/or single/multiple 'Else' Tag.</p>
35:         *
36:         * <!-- END SNIPPET: javadoc -->
37:         *
38:         *
39:         * <!-- START SNIPPET: params -->
40:         *
41:         * <ul>
42:         *
43:         *  <li>test* (Boolean) - Logic to determined if body of tag is to be displayed</li>
44:         *
45:         * </ul>
46:         *
47:         * <!-- END SNIPPET: params -->
48:         *
49:         *
50:         * <pre>
51:         * <!-- START SNIPPET: example -->
52:         *  &lt;s:if test="%{false}"&gt;
53:         *      &lt;div&gt;Will Not Be Executed&lt;/div&gt;
54:         *  &lt;/s:if&gt;
55:         *  &lt;s:elseif test="%{true}"&gt;
56:         *      &lt;div&gt;Will Be Executed&lt;/div&gt;
57:         *  &lt;/s:elseif&gt;
58:         *  &lt;s:else&gt;
59:         *      &lt;div&gt;Will Not Be Executed&lt;/div&gt;
60:         *  &lt;/s:else&gt;
61:         * <!-- END SNIPPET: example -->
62:         * </pre>
63:         *
64:         * @see Else
65:         * @see ElseIf
66:         *
67:         */
68:        @StrutsTag(name="if",tldTagClass="org.apache.struts2.views.jsp.IfTag",description="If tag")
69:        public class If extends Component {
70:            public static final String ANSWER = "struts.if.answer";
71:
72:            Boolean answer;
73:            String test;
74:
75:            @StrutsTagAttribute(description="Expression to determine if body of tag is to be displayed",type="Boolean",required=true)
76:            public void setTest(String test) {
77:                this .test = test;
78:            }
79:
80:            public If(ValueStack stack) {
81:                super (stack);
82:            }
83:
84:            public boolean start(Writer writer) {
85:                answer = (Boolean) findValue(test, Boolean.class);
86:
87:                if (answer == null) {
88:                    answer = Boolean.FALSE;
89:                }
90:                stack.getContext().put(ANSWER, answer);
91:                return answer.booleanValue();
92:            }
93:
94:            public boolean end(Writer writer, String body) {
95:                stack.getContext().put(ANSWER, answer);
96:                return super.end(writer, body);
97:            }
98:        }