/* Copyright (c) 2005 Ricebridge. All Rights Reserved.
 *
 * This file is available under the terms and conditions of the
 * Ricebridge "Open Source API" policy; Ricebridge grants use of this
 * copyrighted work under the terms of a BSD-style license only. See
 * http://www.opensource.org/licenses/bsd-license.php for more
 * information.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 *  - Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following
 *  disclaimer in the documentation and/or other materials provided
 *  with the distribution.
 *
 *  - Neither the name of the Ricebridge nor the names of its
 *  contributors may be used to endorse or promote products derived
 *  from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.  
 */

package com.ricebridge.data.sc;

import com.ricebridge.data.DataException;


/** Convenience class for implementing the {@link StringConverter} interface quickly and easily.
 *    <p>The <code>StringConverter</code> interface requires that you handle the default
 *  parameter option to the {@link StringConverter#makeObject makeObject} and {@link StringConverter#makeString makeString}
 *  methods. This means you have to check for errors and create a {@link DataException} reporting the error, or return the
 *  default value. All this hard is done for you by the <code>DefaultStringConverter</code> class.</p>
 *    <p>All you have to do is implement the {@link #makeObjectImpl(String) makeObjectImpl(String)} 
 *  and {@link #makeStringImpl(Object) makeStringImpl(Object)} methods, and you don't have to worry about handling the default option
 *  at all.</p>
 *    <p>The <b><a href="DefaultStringConverter.java.html">Source Code</a></b> of this Java class 
 *    is available under a <a href="http://www.opensource.org/licenses/bsd-license.php">BSD-style license</a>.</p>
 */
public abstract class DefaultStringConverter extends StringConverterSupport {

  /** Calls the simpler {@link #makeObjectImpl(String) makeObjectImpl(String)} method, and handles the default value automatically. */ 
  protected Object makeObjectImpl( String pValue, boolean pUseDefault ) throws Exception {
    if( null == pValue ) {
      if( pUseDefault ) {
        return makeDefaultObjectImpl();
      }
      else {
        throw new DataException( DataException.CODE_sc_null, new String[]{ "method-type","makeObject"} );
      }
    }
    else {
      try {
        return makeObjectImpl( pValue );
      }
      catch( Exception e ) {
        if( pUseDefault ) { return makeDefaultObjectImpl(); }
        else { throw e; }
      }
    }
  }

  
  /** Return an empty string. 
   *    <p>Override this method if you need a different default object.</p>
   */
  protected Object makeDefaultObjectImpl() {
    return "";
  }


  /** Calls the simpler {@link #makeStringImpl(Object) makeStringImpl(Object)} method, and handles the default value automatically. */ 
  protected String makeStringImpl( Object pValue, boolean pUseDefault ) throws Exception {
    if( null == pValue ) {
      if( pUseDefault ) {
        return makeDefaultStringImpl();
      }
      else {
        throw new DataException( DataException.CODE_sc_null, new String[]{ "method-type","makeString"} );
      }
    }
    else {
      try {
        return makeStringImpl( pValue );
      }
      catch( Exception e ) {
        if( pUseDefault ) { return makeDefaultStringImpl(); }
        else { throw e; }
      }
    }
  }


  /** Return an empty string. 
   *    <p>Override this method if you need a different default text.</p>
   */
  protected String makeDefaultStringImpl() {
    return "";
  }


  /** Implement this method to create an object based on a textual representation.
   *    <p>If an error occurs, just throw an <code>Exception</code>.</p>
   *  @param pValue textual representation
   */
  protected abstract Object makeObjectImpl( String pValue ) throws Exception;


  /** Implement this method to produce a textual representation of an object.
   *    <p>If an error occurs, just throw an <code>Exception</code>.</p>
   *  @param pValue object
   */
  protected abstract String makeStringImpl( Object pValue ) throws Exception;
}