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.trinidad.context;
20
21
22 import java.util.Map;
23
24 import javax.faces.context.FacesContext;
25
26 /**
27 * Abstract implementation for code that provides page flow scopes; this
28 * may be overridden.
29 * <p>
30 * To override this, provide a file on the classpath at
31 * <code>/META-INF/services/org.apache.myfaces.trinidad.context.PageFlowScopeProvider</code>
32 * with the name of the alternative implementation. (There's no current
33 * support for decoration, and this general approach may be revisited
34 * in the future.)
35 * </p>
36 */
37 public abstract class PageFlowScopeProvider
38 {
39 /**
40 */
41 protected PageFlowScopeProvider()
42 {
43 }
44
45 /**
46 * Returns the current PageFlowScope, including any calls
47 * to <code>pushPageFlowScope()</code> or <code>popPageFlowScope()</code>.
48 *
49 * @param context the current FacesContext
50 */
51 public abstract Map<String, Object> getPageFlowScope(FacesContext context);
52
53 /**
54 * Pushes a new process scope onto the stack.
55 *
56 * @param context the current FacesContext
57 * @param copyParent if true, all values from the parent process
58 * scope will be copied into the new process scope.
59 * @return the new scope
60 */
61 public abstract Map<String, Object> pushPageFlowScope(
62 FacesContext context,
63 boolean copyParent);
64
65 /**
66 * Pushes a new process scope onto the stack.
67 *
68 * @param context the current FacesContext
69 * @param discardScope if true, the scope will be immediately destroyed.
70 * if false, the scope may be available (for back button use, for
71 * example), but this is at the discretion of the implementation,
72 * which may aggressively destroy page flow scopes in some circumstances.
73 */
74 public abstract Map<String, Object> popPageFlowScope(FacesContext context, boolean discardScope);
75
76 /**
77 * Encode the page flow scope into the current URL for processing
78 * in later requests.
79 *
80 * @param context the current FacesContext
81 * @param url an URL (which may already contain query parameters)
82 */
83 public abstract String encodeCurrentPageFlowScopeURL(
84 FacesContext context,
85 String url);
86 }