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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;
47  
48  import org.melati.poem.generated.CapabilityTableBase;
49  import java.sql.ResultSet;
50  
51  /**
52   * The {@link Table} of {@link Capability}s.
53   *
54   * Every Melati DB has this table.
55   * This table will contain at least <code>_administer_</code>. 
56   *
57   * Melati POEM generated, programmer modifiable stub 
58   * for a <code>CapabilityTable</code> object.
59   * <p>
60   * Description: 
61   *   A capability which users can be required to possess before accessing 
62   *   data. 
63   * </p>
64   *
65   * 
66   * <table> 
67   * <caption>
68   * Field summary for SQL table <code>Capability</code>
69   * </caption>
70   * <tr><th>Name</th><th>Type</th><th>Description</th></tr>
71   * <tr><td> id </td><td> Integer </td><td> The Table Row Object ID </td></tr> 
72   * <tr><td> name </td><td> String </td><td> A human-readable name for the 
73   * capability </td></tr> 
74   * </table> 
75   * 
76   * See  org.melati.poem.prepro.TableDef#generateTableMainJava 
77   */
78  public class CapabilityTable<T extends Capability> extends CapabilityTableBase<T> {
79  
80   /**
81    * Constructor.
82    * 
83    * See org.melati.poem.prepro.TableDef#generateTableMainJava 
84    * @param database          the POEM database we are using
85    * @param name              the name of this <code>Table</code>
86    * @param definitionSource  which definition is being used
87    * @throws PoemException    if anything goes wrong
88    */
89    public CapabilityTable(Database database, String name,
90                           DefinitionSource definitionSource)
91        throws PoemException {
92      super(database, name, definitionSource);
93    }
94  
95    // programmer's domain-specific code here
96  
97    /** Ensured capability - all db have one. */ 
98    private Capability administer;
99  
100   /** @return the Capability required to administer a database **/ 
101   Capability administer() {
102     return administer;
103   }
104 
105  /**
106   * Ensure that the <tt>_administer_</tt> {@link Capability} 
107   * exists and apply it to this table, also create <tt>canRead</tt>,
108   * <tt>canWrite</tt>, <tt>candelete</tt> and <tt>canSelect</tt> 
109   * as they are referrred to in column definition.
110   *
111   * @param colDescs the {@link Column} descriptions
112   * @see org.melati.poem.Table#defineColumn(Column)
113   */
114   public synchronized void unifyWithDB(ResultSet colDescs, String troidColumnName)
115       throws PoemException {
116     super.unifyWithDB(colDescs, troidColumnName);
117 
118     administer = ensure("_administer_");
119     
120     ensure("canRead");
121     ensure("canWrite");
122     ensure("canDelete");
123     ensure("canSelect");
124 
125   }
126   
127  /**
128   * Retrieve a {@link Capability} by name.
129   *
130   * @param name the name of the {@link Capability} to return
131   * @return the existing {@link Capability}
132   */
133   public Capability get(String name) {
134       return (Capability) getNameColumn().firstWhereEq(name);
135   }
136 
137  /**
138   * Make sure that a record exists.
139   *
140   * @param name the name of the {@link Capability} to ensure
141   * @return the existing or newly created {@link Capability}
142   */
143   public Capability ensure(String name) {
144     Capability capability = get(name);
145     if (capability != null)
146       return capability;
147     else {
148       capability = (Capability)newPersistent();
149       capability.setName(name);
150       return (Capability)getNameColumn().ensure(capability);
151     }
152   }
153 
154 }