001 package org.apache.myfaces.tobago.util;
002
003 /*
004 * Licensed to the Apache Software Foundation (ASF) under one or more
005 * contributor license agreements. See the NOTICE file distributed with
006 * this work for additional information regarding copyright ownership.
007 * The ASF licenses this file to You under the Apache License, Version 2.0
008 * (the "License"); you may not use this file except in compliance with
009 * the License. You may obtain a copy of the License at
010 *
011 * http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 */
019
020 import javax.faces.application.Application;
021 import javax.faces.context.FacesContext;
022 import javax.faces.el.VariableResolver;
023 import javax.faces.el.ValueBinding;
024
025 public class VariableResolverUtil {
026
027 private VariableResolverUtil() {
028 }
029
030 public static Object resolveVariable(FacesContext context, String variable) {
031 Application application = context.getApplication();
032 VariableResolver variableResolver = application.getVariableResolver();
033 return variableResolver.resolveVariable(context, variable);
034 }
035
036 /**
037 * Clears the value of the variable.
038 * Useful for cleaning up e.g. a session or application variable
039 * to save memory without the knowledge of the scope.
040 * Also useful to enforce a new creation of a managed-bean.
041 *
042 * @param context
043 * @param variable
044 */
045 public static void clearVariable(FacesContext context, String variable) {
046 Application application = context.getApplication();
047 ValueBinding valueBinding = application.createValueBinding("#{" + variable + "}");
048 valueBinding.setValue(context, null);
049 }
050 }