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 jakarta.faces.render;
20
21 import java.io.IOException;
22
23 import jakarta.faces.component.UIComponent;
24 import jakarta.faces.context.FacesContext;
25 import jakarta.faces.convert.ConverterException;
26
27 /**
28 * see Javadoc of <a href="http://java.sun.com/javaee/javaserverfaces/1.2/docs/api/index.html">JSF Specification</a>
29 */
30 public abstract class Renderer
31 {
32 /**
33 * @since 2.2
34 */
35 public static final String PASSTHROUGH_RENDERER_LOCALNAME_KEY = "elementName";
36
37 public void decode(FacesContext context, UIComponent component)
38 {
39 if (context == null)
40 {
41 throw new NullPointerException("context");
42 }
43 if (component == null)
44 {
45 throw new NullPointerException("component");
46 }
47 }
48
49 /**
50 * @throws IOException if an input/output error occurs while rendering
51 */
52 public void encodeBegin(FacesContext context, UIComponent component) throws IOException
53 {
54 if (context == null)
55 {
56 throw new NullPointerException("context");
57 }
58 if (component == null)
59 {
60 throw new NullPointerException("component");
61 }
62 }
63
64 /**
65 * Render all children if there are any.
66 *
67 * Note: this will only be called if getRendersChildren() returns true. A component which has a renderer with
68 * getRendersChildren() set to true will typically contain the rendering logic for its children in this method.
69 *
70 * @param context
71 * @param component
72 * @throws IOException
73 */
74 public void encodeChildren(FacesContext context, UIComponent component) throws IOException
75 {
76 if (context == null)
77 {
78 throw new NullPointerException("context");
79 }
80 if (component == null)
81 {
82 throw new NullPointerException("component");
83 }
84
85 if (component.getChildCount() > 0)
86 {
87 for (int i = 0, childCount = component.getChildCount(); i < childCount; i++)
88 {
89 UIComponent child = component.getChildren().get(i);
90 if (!child.isRendered())
91 {
92 continue;
93 }
94
95 child.encodeAll(context);
96 }
97 }
98 }
99
100 /**
101 * @throws IOException if an input/output error occurs while rendering
102 */
103 public void encodeEnd(FacesContext context, UIComponent component) throws IOException
104 {
105 if (context == null)
106 {
107 throw new NullPointerException("context");
108 }
109 if (component == null)
110 {
111 throw new NullPointerException("component");
112 }
113 }
114
115 public String convertClientId(FacesContext context, String clientId)
116 {
117 if (context == null)
118 {
119 throw new NullPointerException("context");
120 }
121 if (clientId == null)
122 {
123 throw new NullPointerException("clientId");
124 }
125 return clientId;
126 }
127
128 /**
129 * Switch for deciding who renders the children.
130 *
131 * @return <b>true</b> - if the component takes care of rendering its children. In this case, encodeChildren() ought
132 * to be called by the rendering controller (e.g., the rendering controller could be the method encodeAll()
133 * in UIComponent). In the method encodeChildren(), the component should therefore provide all children
134 * encode logic. <p></p> <b>false</b> - if the component does not take care of rendering its children.
135 * In this
136 * case, encodeChildren() should not be called by the rendering controller. Instead, the children-list
137 * should be retrieved and the children should directly be rendered by the rendering controller one by one.
138 */
139 public boolean getRendersChildren()
140 {
141 return false;
142 }
143
144 public Object getConvertedValue(FacesContext context, UIComponent component, Object submittedValue)
145 throws ConverterException
146 {
147 if (context == null)
148 {
149 throw new NullPointerException("context");
150 }
151 if (component == null)
152 {
153 throw new NullPointerException("component");
154 }
155 return submittedValue;
156 }
157
158 }