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;
20
21 import javax.el.ELContext;
22 import javax.el.ELException;
23 import javax.el.ValueExpression;
24 import javax.faces.application.Application;
25 import javax.faces.context.FacesContext;
26 import javax.faces.el.EvaluationException;
27 import javax.faces.el.VariableResolver;
28
29 import org.apache.myfaces.el.unified.resolver.FacesCompositeELResolver;
30 import org.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.Scope;
31
32 /**
33 * This variable resolver will be used for legacy variable resolvers which are registered through the faces config. If
34 * it is invoked through the faces chain it will use the el resolver of {@link Application#getELResolver()}. If it is
35 * invoked through the jsp chain it will create an value expression through {@link Application#getExpressionFactory()}
36 * to resolve the variable.
37 *
38 * @author Manfred Geiler (latest modification by $Author$)
39 * @author Anton Koinov
40 * @author Mathias Broekelmann
41 * @version $Revision$ $Date$
42 */
43 @SuppressWarnings("deprecation")
44 public final class VariableResolverImpl extends VariableResolver
45 {
46 @Override
47 public Object resolveVariable(final FacesContext context, final String name) throws EvaluationException
48 {
49 if (context == null)
50 {
51 throw new NullPointerException("context must not be null");
52 }
53 if (name == null)
54 {
55 throw new NullPointerException("name must not be null");
56 }
57
58 try
59 {
60 final Scope scope = getScope(context);
61 final ELContext elcontext = context.getELContext();
62 final Application application = context.getApplication();
63 if (Scope.Faces.equals(scope))
64 {
65 return application.getELResolver().getValue(elcontext, null, name);
66 }
67 else if (Scope.JSP.equals(scope))
68 {
69 ValueExpression expression = application.getExpressionFactory().createValueExpression(elcontext,
70 "#{" + name + "}", Object.class);
71 return expression.getValue(elcontext);
72 }
73 else
74 {
75 throw new IllegalStateException("unknown scope defined: " + scope);
76 }
77 }
78 catch (ELException e)
79 {
80 throw new EvaluationException(e.getMessage(), e);
81 }
82 }
83
84 protected Scope getScope(final FacesContext context)
85 {
86 return (Scope) context.getAttributes().get(FacesCompositeELResolver.SCOPE);
87 }
88 }