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/javaee/javaserverfaces/1.2/docs/api/index.html">JSF Specification</a>
30 *
31 * @author Manfred Geiler (latest modification by $Author: skitching $)
32 * @version $Revision: 676298 $ $Date: 2008-07-13 05:31:48 -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 if (context == null) throw new NullPointerException("context");
66 if (component == null) throw new NullPointerException("component");
67
68 if(component.getChildCount()>0) {
69 for (UIComponent child : component.getChildren()) {
70 if (!child.isRendered()) {
71 continue;
72 }
73
74 child.encodeAll(context);
75 }
76 }
77 }
78
79 public void encodeEnd(FacesContext context,
80 UIComponent component)
81 throws IOException
82 {
83 if (context == null) throw new NullPointerException("context");
84 if (component == null) throw new NullPointerException("component");
85 }
86
87 public String convertClientId(FacesContext context,
88 String clientId)
89 {
90 if (context == null) throw new NullPointerException("context");
91 if (clientId == null) throw new NullPointerException("clientId");
92 return clientId;
93 }
94
95 /**Switch for deciding who renders the children.
96 *
97 * @return <b>true</b> - if the component takes care of rendering its
98 * children. In this case, encodeChildren() ought to be called
99 * by the rendering controller (e.g., the rendering controller
100 * could be the method encodeAll() in UIComponent).
101 * In the method encodeChildren(), the component
102 * should therefore provide all children encode logic.
103 * <br/>
104 * <b>false</b> - if the component does not take care of rendering its
105 * children. In this case, encodeChildren() should not be called
106 * by the rendering controller. Instead, the children-list should
107 * be retrieved and the children should directly be rendered by
108 * the rendering controller one by one.
109 */
110 public boolean getRendersChildren()
111 {
112 return false;
113 }
114
115 public Object getConvertedValue(FacesContext context,
116 UIComponent component,
117 Object submittedValue)
118 throws ConverterException
119 {
120 if (context == null) throw new NullPointerException("context");
121 if (component == null) throw new NullPointerException("component");
122 return submittedValue;
123 }
124
125 }