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.el.unified.resolver.implicitobject;
20
21 import java.beans.FeatureDescriptor;
22 import javax.el.ELContext;
23 import javax.el.ELResolver;
24 import javax.faces.context.ExternalContext;
25 import javax.faces.context.FacesContext;
26
27 /**
28 * Implementors of this class encapsulate the information needed to resolve the implicit object.
29 *
30 * @author Stan Silvert
31 */
32 public abstract class ImplicitObject
33 {
34
35 public abstract Object getValue(ELContext context);
36
37 public abstract FeatureDescriptor getDescriptor();
38
39 /**
40 * Returns an interned String representing the name of the implicit object.
41 */
42 public abstract String getName();
43
44 /**
45 * Returns the most general type allowed for a future call to setValue()
46 */
47 public abstract Class<?> getType();
48
49 protected FeatureDescriptor makeDescriptor(String name, String description, Class<?> elResolverType)
50 {
51 FeatureDescriptor fd = new FeatureDescriptor();
52 fd.setValue(ELResolver.RESOLVABLE_AT_DESIGN_TIME, Boolean.TRUE);
53 fd.setValue(ELResolver.TYPE, elResolverType);
54 fd.setName(name);
55 fd.setDisplayName(name);
56 fd.setShortDescription(description);
57 fd.setExpert(false);
58 fd.setHidden(false);
59 fd.setPreferred(true);
60 return fd;
61 }
62
63 // get the FacesContext from the ELContext
64 protected FacesContext facesContext(ELContext context)
65 {
66 return (FacesContext) context.getContext(FacesContext.class);
67 }
68
69 protected ExternalContext externalContext(ELContext context)
70 {
71 return facesContext(context).getExternalContext();
72 }
73
74 }