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1   /*
2    * $Source$
3    * $Revision$
4    *
5    * Copyright (C) 2000 William Chesters
6    *
7    * Part of Melati (http://melati.org), a framework for the rapid
8    * development of clean, maintainable web applications.
9    *
10   * Melati is free software; Permission is granted to copy, distribute
11   * and/or modify this software under the terms either:
12   *
13   * a) the GNU General Public License as published by the Free Software
14   *    Foundation; either version 2 of the License, or (at your option)
15   *    any later version,
16   *
17   *    or
18   *
19   * b) any version of the Melati Software License, as published
20   *    at http://melati.org
21   *
22   * You should have received a copy of the GNU General Public License and
23   * the Melati Software License along with this program;
24   * if not, write to the Free Software Foundation, Inc.,
25   * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26   * GNU General Public License and visit http://melati.org to obtain the
27   * Melati Software License.
28   *
29   * Feel free to contact the Developers of Melati (http://melati.org),
30   * if you would like to work out a different arrangement than the options
31   * outlined here.  It is our intention to allow Melati to be used by as
32   * wide an audience as possible.
33   *
34   * This program is distributed in the hope that it will be useful,
35   * but WITHOUT ANY WARRANTY; without even the implied warranty of
36   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
37   * GNU General Public License for more details.
38   *
39   * Contact details for copyright holder:
40   *
41   *     William Chesters <williamc At paneris.org>
42   *     http://paneris.org/~williamc
43   *     Obrechtstraat 114, 2517VX Den Haag, The Netherlands
44   */
45  
46  package org.melati.poem.prepro;
47  
48  import java.io.StreamTokenizer;
49  import java.io.IOException;
50  
51  /**
52   * A <tt>FieldQualifier</tt> which defines the type of 
53   * <tt>IntegrityFix</tt> to use with a reference field.
54   *
55   */
56  public class IntegrityfixFieldQualifier extends FieldQualifier {
57  
58    private String integrityfix;
59  
60   /**
61    * Constructor.
62    *
63    * @param tokens the <code>StreamTokenizer</code> to get tokens from
64    *
65    * @throws ParsingDSDException if an unexpected token is encountered
66    * @throws IOException if something goes wrong with the file system
67    */
68    public IntegrityfixFieldQualifier(StreamTokenizer tokens)
69        throws ParsingDSDException, IOException {
70      DSD.expect(tokens, '=');
71      tokens.nextToken();
72      if (tokens.ttype != StreamTokenizer.TT_WORD)
73        throw new ParsingDSDException("<integrity fix name>", tokens);
74      integrityfix = validIntegrityFixNamed(tokens.sval);
75  
76      tokens.nextToken();
77    }
78  
79   /**
80    * Check fix name.
81    * @param sval fix name
82    * @return validated fix name
83    */
84    private String validIntegrityFixNamed(String sval) {
85      if (sval.equals("delete") ||  
86          sval.equals("clear")  ||
87          sval.equals("prevent"))
88        return sval;
89      else 
90        throw new ParsingDSDException("<integrity fix name>: one of delete, clear or prevent", sval);
91    }
92  
93   /**
94    * Thrown when an attempt is made to apply an <code>IntegrityFix</code>
95    * to a field which is not a <code>ReferencePoemType</code>.
96    */
97    public static class ApplicationException extends IllegalityException {
98      private static final long serialVersionUID = 1L;
99  
100     ApplicationException(FieldDef field) {
101       this.field = field;
102       this.lineNumber = field.lineNumber;
103       this.message = "The column " + field + " cannot have an `integrityfix' " +
104       "because that only applies to references";
105     }
106   }
107 
108  /**
109   * Update the model.
110   *
111   * @param field the {@link FieldDef} to update
112   *
113   * @throws IllegalityException if there is a semantic contractiction
114   */
115   public void apply(FieldDef field) throws IllegalityException {
116     if (field instanceof ReferenceFieldDef)
117       ((ReferenceFieldDef)field).setIntegrityFix(integrityfix);
118     else if (field instanceof StringKeyReferenceFieldDef)
119       ((StringKeyReferenceFieldDef)field).setIntegrityFix(integrityfix);
120     else
121       throw new ApplicationException(field);
122   }
123 }