/*

  * $Source$

  * $Revision$

  *

  * Copyright (C) 2000 William Chesters

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) the GNU General Public License as published by the Free Software

  *    Foundation; either version 2 of the License, or (at your option)

  *    any later version,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * Contact details for copyright holder:

  *

  *     William Chesters <williamc At paneris.org>

  *     http://paneris.org/~williamc

  *     Obrechtstraat 114, 2517VX Den Haag, The Netherlands

  */

 package org.melati.poem;

 import java.util.Hashtable;

 import java.util.Enumeration;

 import org.melati.poem.util.ArrayEnumeration;

 /**

  * A set of {@link Field}s accessible in sequence or looked up

  * using an encoding of the table name and column name.

  */

 public class FieldSet {

   private Hashtable<String, Integer> table_columnMap;

   private Field<?>[] fields;

   /**

    * Constructor.

    * @param table_columnMap a Hashtable keyed on tablename underscore fieldname containing indices to fields

    * @param fields an array of fields

    */

   public FieldSet(Hashtable<String, Integer> table_columnMap, Field<?>[] fields) {

     this.table_columnMap = table_columnMap;

     this.fields = fields;

   }

   /**

    * @return an Enumeration of the fields

    */

   public Enumeration<Field<?>> elements() {

     return new ArrayEnumeration<Field<?>>(fields);

   }

   /**

    * Return a specified field.

    *

    * @param name The table name and column name separated by "_".

    * @return a Field with given name or null

    * @see TailoredResultSetEnumeration#mapped(java.sql.ResultSet)

    */

   public Field<?> get(String name) {

     Integer f = (Integer)table_columnMap.get(name);

     return f == null ? null : fields[f.intValue()];

   }

   /**

    * Used to debug tests.

    * {@inheritDoc}

    * @see java.lang.Object#toString()

    */

   public String toString() {

     if (fields != null) {

       String result = "";

         for (int i = 0; i< fields.length; i++) {

           result += fields[i].getName();

           result += "=\"";

           result += fields[i].getCooked();

           result += "\"";

           result += "\n";

         }

       return result;

     } else {

       return null;

     }

   }

 }