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Java > Open Source Codes > org > apache > commons > jelly > impl > StaticTagScript


1 /*
2  * Copyright 2002,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.jelly.impl;
17
18 import org.apache.commons.jelly.DynaTag;
19 import org.apache.commons.jelly.JellyContext;
20 import org.apache.commons.jelly.JellyException;
21 import org.apache.commons.jelly.JellyTagException;
22 import org.apache.commons.jelly.Tag;
23 import org.apache.commons.jelly.TagLibrary;
24 import org.apache.commons.jelly.XMLOutput;
25 import org.apache.commons.jelly.expression.Expression;
26 import org.xml.sax.SAXException JavaDoc;
27
28 import java.net.URL JavaDoc;
29 import java.util.Iterator JavaDoc;
30 import java.util.Map JavaDoc;
31
32 /**
33  * <p><code>StaticTagScript</code> is a script that evaluates a StaticTag, a piece of static XML
34  * though its attributes or element content may contain dynamic expressions.
35  * The first time this tag evaluates, it may have become a dynamic tag, so it will check that
36  * a new dynamic tag has not been generated.</p>
37  *
38  * @author <a HREF="mailto:jstrachan@apache.org">James Strachan</a>
39  * @version $Revision: 239434 $
40  */
41 public class StaticTagScript extends TagScript {
42
43     public StaticTagScript() {
44     }
45
46     public StaticTagScript(TagFactory tagFactory) {
47         super(tagFactory);
48     }
49
50
51     // Script interface
52 //-------------------------------------------------------------------------
53 public void run(JellyContext context, XMLOutput output) throws JellyTagException {
54         try {
55             startNamespacePrefixes(output);
56         } catch (SAXException JavaDoc e) {
57             throw new JellyTagException("could not start namespace prefixes",e);
58         }
59
60         Tag tag;
61         try {
62             tag = getTag(context);
63
64             // lets see if we have a dynamic tag
65 if (tag instanceof StaticTag) {
66                 tag = findDynamicTag(context, (StaticTag) tag);
67             }
68
69             setTag(tag,context);
70         } catch (JellyException e) {
71             throw new JellyTagException(e);
72         }
73
74         URL JavaDoc rootURL = context.getRootURL();
75         URL JavaDoc currentURL = context.getCurrentURL();
76         try {
77             if ( tag == null ) {
78                 return;
79             }
80             tag.setContext(context);
81             setContextURLs(context);
82
83             DynaTag dynaTag = (DynaTag) tag;
84
85             // ### probably compiling this to 2 arrays might be quicker and smaller
86 for (Iterator JavaDoc iter = attributes.entrySet().iterator(); iter.hasNext();) {
87                 Map.Entry JavaDoc entry = (Map.Entry JavaDoc) iter.next();
88                 String JavaDoc name = (String JavaDoc) entry.getKey();
89                 if(name.indexOf(':')!=-1)
90                     name = name.substring(name.indexOf(':')+1);
91                 ExpressionAttribute expat = (ExpressionAttribute) entry.getValue();
92                 Expression expression = expat.exp;
93
94                 Object JavaDoc value;
95
96                 if ( Expression.class.isAssignableFrom( dynaTag.getAttributeType(name) ) ) {
97                     value = expression;
98                 } else {
99                     value = expression.evaluate(context);
100                 }
101
102                 if( expat.prefix != null && expat.prefix.length() > 0 && tag instanceof StaticTag )
103                 {
104                     ((StaticTag) dynaTag).setAttribute(name,expat.prefix, expat.nsURI,value);
105                 }
106                 else
107                 {
108                     dynaTag.setAttribute(name, value);
109                 }
110             }
111
112             tag.doTag(output);
113         }
114         catch (JellyTagException e) {
115             handleException(e);
116         }
117         catch (RuntimeException JavaDoc e) {
118             handleException(e);
119         } finally {
120             context.setCurrentURL(currentURL);
121             context.setRootURL(rootURL);
122         }
123
124         try {
125             endNamespacePrefixes(output);
126         } catch (SAXException JavaDoc e) {
127             throw new JellyTagException("could not end namespace prefixes",e);
128         }
129     }
130
131     /**
132      * Attempts to find a dynamically created tag that has been created since this
133      * script was compiled
134      */
135     protected Tag findDynamicTag(JellyContext context, StaticTag tag) throws JellyException {
136         // lets see if there's a tag library for this URI...
137 TagLibrary taglib = context.getTagLibrary( tag.getUri() );
138         if ( taglib != null ) {
139             Tag newTag = taglib.createTag( tag.getLocalName(), getSaxAttributes() );
140             if ( newTag != null ) {
141                 newTag.setParent( tag.getParent() );
142                 newTag.setBody( tag.getBody() );
143                 return newTag;
144             }
145         }
146         return tag;
147     }
148 }
149
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