/*

  * 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.view.facelets.compiler;

 import java.io.IOException;

 import javax.el.ELContext;

 import javax.el.ELException;

 import javax.el.ExpressionFactory;

 import javax.faces.context.FacesContext;

 import javax.faces.context.ResponseWriter;

 import org.apache.myfaces.view.facelets.el.ELText;

 final class AttributeInstruction implements Instruction

 {

     private final String _alias;

     private final String _attr;

     private final ELText _txt;

     public AttributeInstruction(String alias, String attr, ELText txt)

     {

         _alias = alias;

         _attr = attr;

         _txt = txt;

     }

     public void write(FacesContext context) throws IOException

     {

         ResponseWriter out = context.getResponseWriter();

         try

         {

             out.writeAttribute(_attr, _txt.toString(context.getELContext()), null);

         }

         catch (ELException e)

         {

             throw new ELException(_alias + ": " + e.getMessage(), e.getCause());

         }

         catch (Exception e)

         {

             throw new ELException(_alias + ": " + e.getMessage(), e);

         }

     }

     public Instruction apply(ExpressionFactory factory, ELContext ctx)

     {

         ELText nt = _txt.apply(factory, ctx);

         if (nt == _txt)

         {

             return this;

         }

         return new AttributeInstruction(_alias, _attr, nt);

     }

     public boolean isLiteral()

     {

         return _txt.isLiteral();

     }

 }