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Java > Open Source Codes > org > apache > commons > betwixt > digester > TextRule


1 package org.apache.commons.betwixt.digester;
2
3 /*
4  * Copyright 2001-2004 The Apache Software Foundation.
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18
19 import java.beans.PropertyDescriptor JavaDoc;
20 import java.lang.reflect.Method JavaDoc;
21
22 import org.apache.commons.betwixt.ElementDescriptor;
23 import org.apache.commons.betwixt.TextDescriptor;
24 import org.apache.commons.betwixt.XMLBeanInfo;
25 import org.apache.commons.betwixt.expression.ConstantExpression;
26 import org.apache.commons.betwixt.expression.MethodExpression;
27 import org.apache.commons.betwixt.expression.MethodUpdater;
28 import org.apache.commons.logging.Log;
29 import org.apache.commons.logging.LogFactory;
30 import org.xml.sax.Attributes JavaDoc;
31 import org.xml.sax.SAXException JavaDoc;
32
33 /**
34   * <p>Rule for parsing &lt;text&gt; elements.
35   * These allow mixed content text to be specified.
36   * A mixed content element example:
37   * <pre>
38   * &lt;foo&gt;text&lt;bar/&gt;&lt;/foo&gt;
39   * </pre>
40   * </p>
41   *
42   * @author Robert Burrell Donkin
43   * @version $Id: TextRule.java,v 1.9 2004/06/13 21:32:45 rdonkin Exp $
44   */
45 public class TextRule extends MappedPropertyRule {
46
47     /** Logger */
48     private static final Log log = LogFactory.getLog( TextRule.class );
49     /** Base constructor */
50     public TextRule() {}
51     
52     // Rule interface
53 //-------------------------------------------------------------------------
54
55     /**
56      * Process the beginning of this element.
57      *
58      * @param attributes The attribute list of this element
59      * @throws SAXException 1. If this tag's parent is not an element tag.
60      * 2. If this tag has a value attribute together with either a property
61      * or type attribute.
62      */
63     public void begin(String JavaDoc name, String JavaDoc namespace, Attributes JavaDoc attributes) throws SAXException JavaDoc {
64         
65         TextDescriptor descriptor = new TextDescriptor();
66         
67         String JavaDoc value = attributes.getValue( "value" );
68         String JavaDoc propertyName = attributes.getValue( "property" );
69         String JavaDoc propertyType = attributes.getValue( "type" );
70         
71         if ( value != null) {
72             if ( propertyName != null || propertyType != null ) {
73                 // not allowed
74 throw new SAXException JavaDoc(
75                     "You cannot specify attribute 'value' together with either "
76                     + " the 'property' or 'type' attributes");
77             }
78             // fixed value text
79 descriptor.setTextExpression( new ConstantExpression( value ) );
80             
81         } else {
82             // property based text
83 descriptor.setPropertyName( propertyName );
84             
85             Class JavaDoc beanClass = getBeanClass();
86             
87             // set the property type using reflection
88 descriptor.setPropertyType(
89                 getPropertyType( propertyType, beanClass, propertyName )
90             );
91             
92             if ( beanClass != null ) {
93                 String JavaDoc descriptorPropertyName = descriptor.getPropertyName();
94                 PropertyDescriptor JavaDoc propertyDescriptor =
95                     getPropertyDescriptor( beanClass, descriptorPropertyName );
96                 if ( propertyDescriptor != null ) {
97                         Method JavaDoc readMethod = propertyDescriptor.getReadMethod();
98                         descriptor.setTextExpression( new MethodExpression( readMethod ) );
99                         Method JavaDoc writeMethod = propertyDescriptor.getWriteMethod();
100                         if (writeMethod != null) {
101                             descriptor.setUpdater( new MethodUpdater(writeMethod));
102                         }
103                         getProcessedPropertyNameSet().add( descriptorPropertyName );
104                 }
105             }
106         }
107         
108         Object JavaDoc top = digester.peek();
109         if ( top instanceof XMLBeanInfo ) {
110             XMLBeanInfo beanInfo = (XMLBeanInfo) top;
111             ElementDescriptor elementDescriptor = beanInfo.getElementDescriptor();
112             if (elementDescriptor == null) {
113                 elementDescriptor.addContentDescriptor( descriptor );
114             }
115             
116         } else if ( top instanceof ElementDescriptor ) {
117             ElementDescriptor parent = (ElementDescriptor) top;
118             parent.addContentDescriptor( descriptor );
119             
120         } else {
121             throw new SAXException JavaDoc( "Invalid use of <text>. It should "
122                 + "be nested <text> nodes" );
123         }
124     }
125 }
126
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