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1   /*
2    * $Source$
3    * $Revision$
4    *
5    * Copyright (C) 2012 Tim Pizey
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   *     Tim Pizey <timp At paneris.org>
42   *     http://paneris.org/~timp
43   */
44  
45  package org.melati.poem;
46  
47  import java.util.Enumeration;
48  
49  import org.melati.poem.util.MappedEnumeration;
50  import org.melati.poem.util.StringUtils;
51  
52  /**
53   * A data type that is a reference to a {@link Persistent} object via a 
54   * String key to a unique, non-nullable index.
55   * NOTE: The field may be a different size to the field in the target table. 
56   *
57   * @author timp
58   * @since 2012-05-19
59   */
60  public class StringKeyReferencePoemType extends StringKeyPoemType implements PersistentReferencePoemType, PoemType<String> {
61  
62    private Table<?> targetTable;
63    
64    private String targetKeyName;
65  
66    /**
67     * Constructor.
68     * 
69     * @param targetTable the Table the type refers to 
70     * @param targetKeyName name of key both in this and target table
71     * @param nullable whether this type may contain null values
72     * @param size the size of the key string
73     */
74    public StringKeyReferencePoemType(Table<?> targetTable, 
75        String targetKeyName, boolean nullable, int size) {
76      super(nullable, size);
77      if (targetTable == null)
78        throw new NullPointerException();
79      this.targetTable = targetTable;
80      if (targetKeyName == null)
81        throw new NullPointerException();
82      this.targetKeyName = targetKeyName;
83    }
84  
85    /**
86     * @see org.melati.poem.PersistentReferencePoemType#targetTable()
87     */
88    @Override
89    public Table<?> targetTable() {
90      return targetTable;
91    }
92  
93    /** @return the key name in target table, also this table */ 
94    public String targetKeyName() { 
95      return targetKeyName;
96    }
97    /**
98     * Returns an <code>Enumeration</code> of the possible raw values.
99     * <p>
100    * In this case the key values of rows in the referenced table.
101    */
102   @SuppressWarnings({ "unchecked", "rawtypes" })
103   protected Enumeration<String> _possibleRaws() {
104     return new MappedEnumeration(targetTable.selection()) {
105       public String mapped(Object p) {
106         return (String)((Persistent)p).getRaw(targetKeyName);
107       }
108     };
109   }
110 
111   protected void _assertValidCooked(Object cooked)
112       throws ValidationPoemException {
113     if (!(cooked instanceof Persistent))
114       throw new TypeMismatchPoemException(cooked, this);
115 
116     Persistent persistent = (Persistent)cooked;
117 
118     if (persistent.getTable() != targetTable)
119       throw new ValidationPoemException(
120           this, persistent,
121           new TableMismatchPoemException(persistent, targetTable));
122   }
123 
124   protected Object _cookedOfRaw(Object raw) throws NoSuchRowPoemException {
125     return targetTable.getColumn(targetKeyName).firstWhereEq(raw);
126   }
127 
128   /** 
129    * NOTE that it is expected that the targetKeyName is also 
130    * the name of the field in this persistent.
131    */
132   protected String  _rawOfCooked(Object cooked) {
133     return (String) ((Persistent)cooked).getField(targetKeyName).getRawString();
134   }
135 
136   protected String _stringOfCooked(Object cooked, 
137                                    PoemLocale locale, int style)
138       throws PoemException {
139     return ((Persistent)cooked).displayString(locale, style);
140   }
141 
142   protected boolean _canRepresent(SQLPoemType<?> other) {
143     return
144         other instanceof StringKeyReferencePoemType &&
145         ((StringKeyReferencePoemType)other).targetTable == targetTable;
146   }
147 
148   protected void _saveColumnInfo(ColumnInfo columnInfo)
149       throws AccessPoemException {
150     columnInfo.setTypefactoryCode(targetTable.tableInfoID());
151     columnInfo.setSize(getSize());
152   }
153 
154   /**
155    * {@inheritDoc}
156    * @see org.melati.poem.BasePoemType#toString()
157    */
158   public String toString() {
159     return
160         "string key reference to " + targetTable.getName() + 
161         " on " + targetKeyName +
162         " (" + super.toString() + ")";
163   }
164 
165   /**
166    * {@inheritDoc}
167    * @see org.melati.poem.PoemType#toDsdType()
168    */
169   public String toDsdType() {
170     return StringUtils.capitalised(targetTable.getName() + " StringKeyReference on " + targetKeyName);
171   }
172 }