trunk_failed_1.0_release/extscript-examples/myfaces12-example/src/main/webapp/WEB-INF/java/org/apache/myfaces/javaloader/blog/JSFUtil.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.myfaces.javaloader.blog;

import javax.faces.context.FacesContext;
import java.util.logging.Logger;

import static org.apache.myfaces.extensions.scripting.core.util.ReflectUtil.executeMethod;

/**
 * @author werpu2
 * @date: 01.09.2009
 * <p/>
 * A helper for JSF and introspection related tasks
 */
public class JSFUtil {

    public JSFUtil() {
    }

    /**
     * resolves a variable in the current facesContext
     *
     * @param beanName
     * @return
     */
    public static Object resolveVariable(String beanName) {
        Logger log = Logger.getLogger(JSFUtil.class.getName());
        Object facesContext = FacesContext.getCurrentInstance();

        Object elContext = executeMethod(facesContext, "getELContext");
        Object elResolver = executeMethod(elContext, "getELResolver");

        /*
         if you want to enable this then use
         org.apache.myfaces.extensions.scripting.java.JAR_PATHS
         pointing towards the lingering jars
         The compiler cannot pick up the implicit containers classpaths
        */
        //we use the introspection calls here to achieve our goal that way
        //we can shift the dependency resolution from compile time to runtime
        return executeMethod(elResolver, "getValue", elContext, null, beanName);
        // return FacesContext.getCurrentInstance().getELContext().getELResolver().getValue(FacesContext.getCurrentInstance().getELContext(), null, beanName);

    }

}