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Java > Open Source Codes > org > apache > commons > jelly > tags > define > TaglibTag


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.tags.define;
17
18 import org.apache.commons.jelly.JellyTagException;
19 import org.apache.commons.jelly.TagSupport;
20 import org.apache.commons.jelly.XMLOutput;
21 import org.apache.commons.jelly.impl.DynamicTagLibrary;
22
23 /**
24  * The <taglib> tag is used to define a new tag library
25  * using a Jelly script. The tag library is identified by its
26  * {@link #getURI() URI}.
27  *
28  * The tags for a taglib are declared using the {@link TagTag}.
29  *
30  * You can 'inherit' tags from a previously defined taglib, as well,
31  * allowing runtime extension of tag libraries
32  *
33  * @author <a HREF="mailto:jstrachan@apache.org">James Strachan</a>
34  * @version $Revision: 155420 $
35  */
36 public class TaglibTag extends TagSupport {
37
38     /** The namespace URI */
39     private String JavaDoc uri;
40     /** The new tags being added */
41     private DynamicTagLibrary tagLibrary;
42     /** Whether or not inheritence is enabled */
43     private boolean inherit = true;
44
45     public TaglibTag() {
46     }
47
48     public TaglibTag(String JavaDoc uri) {
49         this.uri = uri;
50     }
51
52     // Tag interface
53 //-------------------------------------------------------------------------
54 public void doTag(XMLOutput output) throws JellyTagException {
55         String JavaDoc uri = getUri();
56         tagLibrary = new DynamicTagLibrary( uri );
57
58         // inherit tags from an existing tag library
59 if ( isInherit() ) {
60             tagLibrary.setParent( context.getTagLibrary( uri ) );
61         }
62         context.registerTagLibrary( uri, tagLibrary );
63
64         invokeBody(output);
65
66         tagLibrary = null;
67     }
68
69     // Properties
70 //-------------------------------------------------------------------------
71 public String JavaDoc getUri() {
72         return uri;
73     }
74
75     /**
76      * Sets the namespace URI to register this new dynamic tag library with
77      */
78     public void setUri(String JavaDoc uri) {
79         this.uri = uri;
80     }
81
82     public DynamicTagLibrary getTagLibrary() {
83         return tagLibrary;
84     }
85
86     /**
87      * Returns the inherit.
88      * @return boolean
89      */
90     public boolean isInherit() {
91         return inherit;
92     }
93
94     /**
95      * Sets whether this dynamic tag should inherit from the current existing tag library
96      * of the same URI. This feature is enabled by default so that tags can easily be
97      * some tags can be overridden in an existing library, such as when making Mock Tags.
98      *
99      * You can disable this option if you want to disable any tags in the base library,
100      * turning them into just normal static XML.
101      *
102      * @param inherit The inherit to set
103      */
104     public void setInherit(boolean inherit) {
105         this.inherit = inherit;
106     }
107
108 }
109
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