View Javadoc

1   /*
2    * Copyright (c) 2002-2014, Mairie de Paris
3    * All rights reserved.
4    *
5    * Redistribution and use in source and binary forms, with or without
6    * modification, are permitted provided that the following conditions
7    * are met:
8    *
9    *  1. Redistributions of source code must retain the above copyright notice
10   *     and the following disclaimer.
11   *
12   *  2. Redistributions in binary form must reproduce the above copyright notice
13   *     and the following disclaimer in the documentation and/or other materials
14   *     provided with the distribution.
15   *
16   *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
17   *     contributors may be used to endorse or promote products derived from
18   *     this software without specific prior written permission.
19   *
20   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
24   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30   * POSSIBILITY OF SUCH DAMAGE.
31   *
32   * License 1.0
33   */
34  package fr.paris.lutece.plugins.formengine.service.output;
35  
36  import fr.paris.lutece.plugins.formengine.web.Form;
37  
38  
39  /**
40   * This interface defines an id generator
41   */
42  public abstract class IdGenerator
43  {
44      /**
45       * Constructor
46       */
47      public IdGenerator(  )
48      {
49      }
50  
51      /**
52       * This method is called by getNewId to initialise the settings
53       * needed by loadId and storeId
54       * @param form the form calling the generator
55       */
56      protected abstract void init( Form form );
57  
58      /**
59       * Returns the current stored id
60       * @return the current id
61       */
62      protected abstract String loadId(  );
63  
64      /**
65       * Stores a new id
66       * @param strId the id to store
67       */
68      protected abstract void storeId( String strId );
69  
70      /**
71       * This method is the one responsible of generating a new id dependind on the
72       * previous id's value
73       * @param form the form calling the idgenerator
74       * @param strCurrentId the current value of the id
75       * @return the new value of the id
76       */
77      protected abstract String updateId( Form form, String strCurrentId );
78  
79      /**
80       * Provides a new id value to the calling form
81       * i.e. :
82       * - initialises the generator<br>
83       * - loads the current id stored<br>
84       * - generates a new id value depending on the current value<br>
85       * - stores the new id value<br>
86       * - return the new id value
87       * @param form the calling form
88       * @return the generated id
89       */
90      public synchronized String getNewId( Form form )
91      {
92          init( form );
93  
94          String strId = loadId(  );
95          strId = updateId( form, strId );
96          storeId( strId );
97  
98          return strId;
99      }
100 }