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 * @param context 042 * @param variable 043 */ 044 public static void clearVariable(FacesContext context, String variable) { 045 Application application = context.getApplication(); 046 ValueBinding valueBinding = application.createValueBinding("#{" + variable + "}"); 047 valueBinding.setValue(context, null); 048 } 049 }