/*
    * Copyright (C) 2007-2012 Argeo GmbH
    *
    * Licensed 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.argeo.slc.core.execution;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.springframework.beans.factory.FactoryBean;
  
  public class ParameterRef implements FactoryBean<Object> {
  	private final static Log log = LogFactory.getLog(ParameterRef.class);
  
  	private InstantiationManager instantiationManager;
  	private String name;
  
  	/** Cached object. */
  	private Object object;
  
  	public ParameterRef() {
  	}
  
  	public ParameterRef(String name) {
  		this.name = name;
  	}
  
  	public Object getObject() throws Exception {
  		if (log.isTraceEnabled())
  			log.debug("Parameter ref called for " + name);
  
  		if (object == null)
  			object = instantiationManager.getInitializingFlowParameter(name);
  		return object;
  	}
  
  	public Class<?> getObjectType() {
  		if (object == null)
  			return instantiationManager.getInitializingFlowParameterClass(name);
  		else
  			return object.getClass();
  	}
  
  	public boolean isSingleton() {
  		return true;
  	}
  
  	public void setInstantiationManager(
  			InstantiationManager instantiationManager) {
  		this.instantiationManager = instantiationManager;
  	}
  
  	public void setName(String name) {
  		this.name = name;
  	}
  
  }