/*

  * $Id: AbstractModelBody.java 1692328 2015-07-22 21:16:35Z mck $

  *

  * 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.tiles.autotag.core.runtime;

 import java.io.IOException;

 import java.io.StringWriter;

 import java.io.Writer;

 import java.util.regex.Pattern;

 import org.apache.tiles.autotag.core.runtime.util.NullWriter;

 /**

  * Base class for the abstraction of the body.

  *

  * @version $Rev: 1692328 $ $Date: 2015-07-22 23:16:35 +0200 (Wed, 22 Jul 2015) $

  */

 public abstract class AbstractModelBody implements ModelBody {

     // precompiled the pattern to avoid compiling on every method call

     private static final Pattern PATTERN = Pattern.compile("^\\s*|\\s*$");

     /**

      * The default writer to use.

      */

     private Writer defaultWriter;

     /**

      * Constructor.

      *

      * @param defaultWriter The default writer to use.

      */

     public AbstractModelBody(Writer defaultWriter) {

         this.defaultWriter = defaultWriter;

     }

     @Override

     public void evaluate() throws IOException {

         evaluate(defaultWriter);

     }

     @Override

     public String evaluateAsString() throws IOException {

         StringWriter writer = new StringWriter();

         try {

             evaluate(writer);

         } finally {

             writer.close();

         }

         String body = writer.toString();

         if (body != null) {

             body = PATTERN.matcher(body).replaceAll("");

             if (body.length() <= 0) {

                 body = null;

             }

         }

         return body;

     }

     @Override

     public void evaluateWithoutWriting() throws IOException {

         NullWriter writer = new NullWriter();

         try {

             evaluate(writer);

         } finally {

             writer.close();

         }

     }

 }