/*
    * 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.flow;
  
  import javax.el.ValueExpression;
  import javax.faces.context.FacesContext;
  import javax.faces.flow.ReturnNode;
  
  /**
   *
   * @since 2.2
   * @author Leonardo Uribe
   */
  public class ReturnNodeImpl extends ReturnNode implements Freezable
  {
      private String _fromOutcome;
      private ValueExpression _fromOutcomeEL;
      private String _id;
  
      private boolean _initialized;
  
      public ReturnNodeImpl(String returnNodeId)
      {
          this._id = returnNodeId;
      }
      
      @Override
      public String getFromOutcome(FacesContext context)
      {
          if (_fromOutcomeEL != null)
          {
              return (String) _fromOutcomeEL.getValue(context.getELContext());
          }
          return _fromOutcome;
      }
  
      @Override
      public String getId()
      {
          return _id;
      }
      
      public void freeze()
      {
          _initialized = true;
      }
      
      private void checkInitialized() throws IllegalStateException
      {
          if (_initialized)
          {
              throw new IllegalStateException("Flow is inmutable once initialized");
          }
      }
  
      public void setFromOutcome(String fromOutcome)
      {
          checkInitialized();
          this._fromOutcome = fromOutcome;
          this._fromOutcomeEL = null;
      }
      
      public void setFromOutcome(ValueExpression fromOutcome)
      {
          checkInitialized();
          this._fromOutcomeEL = fromOutcome;
          this._fromOutcome = null;
      }
  
      public void setId(String id)
      {
          checkInitialized();
          this._id = id;
      }
  }