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Java > Open Source Codes > org > apache > jasper > tagplugins > jstl > core > Out


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
19 package org.apache.jasper.tagplugins.jstl.core;
20
21 import org.apache.jasper.compiler.tagplugin.TagPlugin;
22 import org.apache.jasper.compiler.tagplugin.TagPluginContext;
23
24
25 public final class Out implements TagPlugin {
26     
27     public void doTag(TagPluginContext ctxt) {
28         
29         //these two data member are to indicate
30 //whether the corresponding attribute is specified
31 boolean hasDefault=false, hasEscapeXml=false;
32         hasDefault = ctxt.isAttributeSpecified("default");
33         hasEscapeXml = ctxt.isAttributeSpecified("escapeXml");
34         
35         //strValName, strEscapeXmlName & strDefName are two variables' name
36 //standing for value, escapeXml and default attribute
37 String JavaDoc strValName = ctxt.getTemporaryVariableName();
38         String JavaDoc strDefName = ctxt.getTemporaryVariableName();
39         String JavaDoc strEscapeXmlName = ctxt.getTemporaryVariableName();
40         
41         //according to the tag file, the value attribute is mandatory.
42 ctxt.generateJavaSource("String " + strValName + " = null;");
43         ctxt.generateJavaSource("if(");
44         ctxt.generateAttribute("value");
45         ctxt.generateJavaSource("!=null){");
46         ctxt.generateJavaSource(" " + strValName + " = (");
47         ctxt.generateAttribute("value");
48         ctxt.generateJavaSource(").toString();");
49         ctxt.generateJavaSource("}");
50         
51         //initiate the strDefName with null.
52 //if the default has been specified, then assign the value to it;
53 ctxt.generateJavaSource("String " + strDefName + " = null;\n");
54         if(hasDefault){
55             ctxt.generateJavaSource("if(");
56             ctxt.generateAttribute("default");
57             ctxt.generateJavaSource(" != null){");
58             ctxt.generateJavaSource(strDefName + " = (");
59             ctxt.generateAttribute("default");
60             ctxt.generateJavaSource(").toString();");
61             ctxt.generateJavaSource("}");
62         }
63         
64         //initiate the strEscapeXmlName with true;
65 //if the escapeXml is specified, assign the value to it;
66 ctxt.generateJavaSource("boolean " + strEscapeXmlName + " = true;");
67         if(hasEscapeXml){
68             ctxt.generateJavaSource(strEscapeXmlName + " = Boolean.parseBoolean((");
69             ctxt.generateAttribute("default");
70             ctxt.generateJavaSource(").toString());");
71         }
72         
73         //main part.
74 ctxt.generateJavaSource("if(null != " + strValName +"){");
75         ctxt.generateJavaSource(" if(" + strEscapeXmlName + "){");
76         ctxt.generateJavaSource(" " + strValName + " = org.apache.jasper.tagplugins.jstl.Util.escapeXml(" + strValName + ");");
77         ctxt.generateJavaSource(" }");
78         ctxt.generateJavaSource(" out.write(" + strValName + ");");
79         ctxt.generateJavaSource("}else{");
80         ctxt.generateJavaSource(" if(null != " + strDefName + "){");
81         ctxt.generateJavaSource(" if(" + strEscapeXmlName + "){");
82         ctxt.generateJavaSource(" " + strDefName + " = org.apache.jasper.tagplugins.jstl.Util.escapeXml(" + strDefName + ");");
83         ctxt.generateJavaSource(" }");
84         ctxt.generateJavaSource(" out.write(" + strDefName + ");");
85         ctxt.generateJavaSource(" }else{");
86         ctxt.generateBody();
87         ctxt.generateJavaSource(" }");
88         ctxt.generateJavaSource("}");
89     }
90 }
91
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