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.view;
20
21 import java.util.Collection;
22 import java.util.Collections;
23 import java.util.Iterator;
24 import java.util.LinkedList;
25
26 import javax.faces.component.UIComponent;
27 import javax.faces.component.UIViewParameter;
28 import javax.faces.component.UIViewRoot;
29 import javax.faces.context.FacesContext;
30
31 /**
32 * @author Simon Lessard (latest modification by $Author: struberg $)
33 * @version $Revision: 1188565 $ $Date: 2011-10-25 03:38:53 -0500 (Tue, 25 Oct 2011) $
34 *
35 * @since 2.0
36 */
37 public abstract class ViewMetadata
38 {
39 public abstract UIViewRoot createMetadataView(FacesContext context);
40
41 public abstract String getViewId();
42
43 public static Collection<UIViewParameter> getViewParameters(UIViewRoot root)
44 {
45 LinkedList<UIViewParameter> result = null;
46 UIComponent metadataFacet = root.getFacet (UIViewRoot.METADATA_FACET_NAME);
47 Iterator<UIComponent> children;
48
49 if (metadataFacet == null)
50 {
51 // No metadata, so return an empty collection.
52
53 return Collections.emptyList();
54 }
55
56 // Iterate over all the children, keep only the view parameters.
57
58 if (metadataFacet.getChildCount() > 0)
59 {
60 children = metadataFacet.getChildren().iterator();
61
62 while (children.hasNext())
63 {
64 UIComponent component = children.next();
65
66 if (result == null)
67 {
68 result = new LinkedList<UIViewParameter>();
69 }
70
71 if (component instanceof UIViewParameter)
72 {
73 result.add ((UIViewParameter) component);
74 }
75 }
76 }
77
78 // TODO: does this need to be immutable? Spec does not indicate either
79 // way.
80 if (result == null)
81 {
82 return Collections.emptyList();
83 }
84 else
85 {
86 return Collections.unmodifiableCollection (result);
87 }
88 }
89 }