1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. 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,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package javax.faces.render;
20
21 import java.io.IOException;
22 import java.util.List;
23
24 import javax.faces.component.UIComponent;
25 import javax.faces.context.FacesContext;
26 import javax.faces.convert.ConverterException;
27
28 /**
29 * see Javadoc of <a href="http://java.sun.com/j2ee/javaserverfaces/1.1_01/docs/api/index.html">JSF Specification</a>
30 *
31 * @author Manfred Geiler (latest modification by $Author: skitching $)
32 * @version $Revision: 676278 $ $Date: 2008-07-13 03:35:04 -0500 (Sun, 13 Jul 2008) $
33 */
34 public abstract class Renderer
35 {
36 public void decode(FacesContext context,
37 UIComponent component)
38 {
39 if (context == null) throw new NullPointerException("context");
40 if (component == null) throw new NullPointerException("component");
41 }
42
43 public void encodeBegin(FacesContext context,
44 UIComponent component)
45 throws IOException
46 {
47 if (context == null) throw new NullPointerException("context");
48 if (component == null) throw new NullPointerException("component");
49 }
50
51 /**Render all children if there are any.
52 *
53 * Note: this will only be called if getRendersChildren()
54 * returns true. A component which has a renderer with
55 * getRendersChildren() set to true will typically contain
56 * the rendering logic for its children in this method.
57 *
58 * @param context
59 * @param component
60 * @throws IOException
61 */
62 public void encodeChildren(FacesContext context,
63 UIComponent component)
64 throws IOException
65 {
66 if (context == null) throw new NullPointerException("context");
67 if (component == null) throw new NullPointerException("component");
68
69 List children = component.getChildren();
70 for (int i=0; i<children.size(); i++)
71 {
72 UIComponent child = (UIComponent) children.get(i);
73
74 if (!child.isRendered())
75 {
76 continue;
77 }
78
79 child.encodeBegin(context);
80 if (child.getRendersChildren())
81 {
82 child.encodeChildren(context);
83 }
84 else {
85 encodeChildren(context, child);
86 }
87 child.encodeEnd(context);
88 }
89 }
90
91
92 public void encodeEnd(FacesContext context,
93 UIComponent component)
94 throws IOException
95 {
96 if (context == null) throw new NullPointerException("context");
97 if (component == null) throw new NullPointerException("component");
98 }
99
100 public String convertClientId(FacesContext context,
101 String clientId)
102 {
103 if (context == null) throw new NullPointerException("context");
104 if (clientId == null) throw new NullPointerException("clientId");
105 return clientId;
106 }
107
108 /**Switch for deciding who renders the children.
109 *
110 * @return <b>true</b> - if the component takes care of rendering its
111 * children. In this case, encodeChildren() ought to be called
112 * by the rendering controller (e.g., the rendering controller
113 * could be the component's JSP-Tag).
114 * In the method encodeChildren(), the component
115 * should therefore provide all children encode logic.
116 * <br/>
117 * <b>false</b> - if the component does not take care of rendering its
118 * children. In this case, encodeChildren() should not be called
119 * by the rendering controller. Instead, the children-list should
120 * be retrieved and the children should directly be rendered by
121 * the rendering controller one by one.
122 */
123 public boolean getRendersChildren()
124 {
125 return false;
126 }
127
128 public Object getConvertedValue(FacesContext context,
129 UIComponent component,
130 Object submittedValue)
131 throws ConverterException
132 {
133 if (context == null) throw new NullPointerException("context");
134 if (component == null) throw new NullPointerException("component");
135 return submittedValue;
136 }
137
138 }