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 org.apache.myfaces.shared.renderkit.html;
20
21 import org.apache.myfaces.shared.renderkit.JSFAttr;
22
23 import javax.faces.application.ViewHandler;
24 import javax.faces.component.UIComponent;
25 import javax.faces.component.UIViewRoot;
26 import javax.faces.context.FacesContext;
27 import javax.faces.render.Renderer;
28 import java.io.IOException;
29 import java.util.List;
30
31 /**
32 * @author Manfred Geiler (latest modification by $Author: lu4242 $)
33 * @version $Revision: 1230324 $ $Date: 2012-01-11 18:21:34 -0500 (Wed, 11 Jan 2012) $
34 */
35 public abstract class HtmlRenderer
36 extends Renderer
37 {
38
39 /**
40 * Return the list of children of the specified component.
41 * <p>
42 * This default implementation simply returns component.getChildren().
43 * However this method should always be used in order to allow
44 * renderer subclasses to override it and provide filtered or
45 * reordered views of the component children to rendering
46 * methods defined in their ancestor classes.
47 * <p>
48 * Any method that overrides this to "hide" child components
49 * should also override the getChildCount method.
50 *
51 * @return a list of UIComponent objects.
52 */
53 public List<UIComponent> getChildren(UIComponent component)
54 {
55 return component.getChildren();
56 }
57
58 /**
59 * Return the number of children of the specified component.
60 * <p>
61 * See {@link #getChildren(UIComponent)} for more information.
62 */
63 public int getChildCount(UIComponent component)
64 {
65 return component.getChildCount();
66 }
67
68 /**
69 * @param facesContext
70 * @return String A String representing the action URL
71 */
72 protected String getActionUrl(FacesContext facesContext)
73 {
74 ViewHandler viewHandler = facesContext.getApplication().getViewHandler();
75 String viewId = facesContext.getViewRoot().getViewId();
76 return viewHandler.getActionURL(facesContext, viewId);
77 }
78
79 /**
80 * Renders the client ID as an "id".
81 */
82 protected void renderId(
83 FacesContext context,
84 UIComponent component) throws IOException
85 {
86 if (shouldRenderId(context, component))
87 {
88 String clientId = getClientId(context, component);
89 context.getResponseWriter().writeAttribute(HTML.ID_ATTR, clientId, JSFAttr.ID_ATTR);
90 }
91 }
92
93 /**
94 * Returns the client ID that should be used for rendering (if
95 * {@link #shouldRenderId} returns true).
96 */
97 protected String getClientId(
98 FacesContext context,
99 UIComponent component)
100 {
101 return component.getClientId(context);
102 }
103
104 /**
105 * Returns true if the component should render an ID. Components
106 * that deliver events should always return "true".
107 * @todo Is this a bottleneck? If so, optimize!
108 */
109 protected boolean shouldRenderId(
110 FacesContext context,
111 UIComponent component)
112 {
113 String id = component.getId();
114
115 // Otherwise, if ID isn't set, don't bother
116 if (id == null)
117 {
118 return false;
119 }
120
121 // ... or if the ID was generated, don't bother
122 if (id.startsWith(UIViewRoot.UNIQUE_ID_PREFIX))
123 {
124 return false;
125 }
126
127 return true;
128 }
129
130 /**
131 * Coerces an object into a URI, accounting for JSF rules
132 * with initial slashes.
133 */
134 static public String toUri(Object o)
135 {
136 if (o == null)
137 {
138 return null;
139 }
140
141 String uri = o.toString();
142 if (uri.startsWith("/"))
143 {
144 // Treat two slashes as server-relative
145 if (uri.startsWith("//"))
146 {
147 uri = uri.substring(1);
148 }
149 else
150 {
151 FacesContext fContext = FacesContext.getCurrentInstance();
152 uri = fContext.getExternalContext().getRequestContextPath() + uri;
153 }
154 }
155
156 return uri;
157 }
158
159 protected boolean isCommonPropertiesOptimizationEnabled(FacesContext facesContext)
160 {
161 return false;
162 }
163
164 protected boolean isCommonEventsOptimizationEnabled(FacesContext facesContext)
165 {
166 return false;
167 }
168 }