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