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Java > Open Source Codes > com > jcorporate > expresso > ext > taglib > ExOutputVarTag


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64
65 package com.jcorporate.expresso.ext.taglib;
66
67 import org.apache.struts.taglib.bean.DefineTag;
68
69 import javax.servlet.jsp.JspException JavaDoc;
70 import javax.servlet.jsp.JspTagException JavaDoc;
71 import javax.servlet.jsp.PageContext JavaDoc;
72 import javax.servlet.jsp.tagext.TagSupport JavaDoc;
73
74
75 /**
76  * Define a scripting variable based on the value(s) of the specified
77  * bean property.
78  *
79  * @author Shash Chatterjee
80  */
81 public class ExOutputVarTag extends DefineTag {
82     // --------------------------------------------------------- Public Methods
83 /**
84      * Retrieve the required property and expose it as a scripting variable.
85      *
86      * @return int as defined by the JSP taglib spec
87      * @throws JspException if a JSP exception has occurred
88      */
89     public int doStartTag()
90             throws JspException JavaDoc {
91
92         return (SKIP_BODY);
93     }
94
95     protected TagSupport JavaDoc getAncestor(String JavaDoc className)
96             throws JspException JavaDoc {
97         Class JavaDoc klass = null;
98
99         try {
100             klass = Class.forName(className);
101         } catch (ClassNotFoundException JavaDoc ex) {
102             throw new JspException JavaDoc(ex.getMessage());
103         }
104
105         return (TagSupport JavaDoc) findAncestorWithClass(this, klass);
106     }
107
108     /**
109      * Retrieve the required property and expose it as a scripting variable.
110      *
111      * @throws JspException if a JSP exception has occurred
112      */
113     public int doEndTag() throws JspException JavaDoc {
114
115
116         // Retrieve the required property value
117 Object JavaDoc value = this.value;
118
119         if ((value == null) && (body != null)) {
120             // Allow body content to become the value if specified
121 value = body;
122         }
123         if (value == null) {
124
125             //Check to see if we have an ancestor
126 OutputTag ancestorOutput = (OutputTag) getAncestor("com.jcorporate.expresso.ext.taglib.OutputTag");
127
128             if (ancestorOutput == null) {
129                 throw new JspTagException JavaDoc("A ExOutputVar tag must be nested within a valid OutputTag.");
130             }
131
132             value = ancestorOutput.getContent();
133         }
134         if (value == null) {
135             throw new JspException JavaDoc("Unable to retireve content from parent Output tag");
136         }
137
138         // Expose this value as a scripting variable
139 int inScope = PageContext.PAGE_SCOPE;
140
141         if ("request".equals(toScope)) {
142             inScope = PageContext.REQUEST_SCOPE;
143         } else if ("session".equals(toScope)) {
144             inScope = PageContext.SESSION_SCOPE;
145         } else if ("application".equals(toScope)) {
146             inScope = PageContext.APPLICATION_SCOPE;
147         }
148
149         pageContext.setAttribute(id, value, inScope);
150
151         // Continue processing this page
152 return (EVAL_PAGE);
153
154     }
155
156 }
157
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