Coverage Report

Coverage Report - net.wotonomy.control.EODataSource

Classes in this File

1.125

 /*
 Wotonomy: OpenStep design patterns for pure Java applications.
 Copyright (C) 2000 Michael Powers
 
 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.
 
 This library 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
 Lesser General Public License for more details.
 
 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, see http://www.gnu.org
 */
 
 package net.wotonomy.control;
 
 import net.wotonomy.foundation.NSArray;
 
 /**
 * EODataSource is used by EODisplayGroup.fetch() to retrieve
 * a list of objects to display.  When a display group has a
 * data source, the display group will use the data source to
 * populate the object list and to create new objects to be 
 * displayed in the list, and will update the data source when
 * objects are inserted or removed from the list. <br><br>
 *
 * In certain cases, as when a display group needs to populate
 * a child display group to show a one-to-many relationship,
 * the display group will call dataSourceQualifiedByKey to
 * return a new data source that can vend objects associated
 * with the specified key and then call qualifyWithRelationshipKey
 * to specify the object and key that are the source of the 
 * child relationship. <br><br>
 *
 * Concrete subclasses are expected to override fetch() and 
 * are required to override insertObject and removeObject.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 894 $
 */
 public abstract class EODataSource
 {
     /**
     * Creates a new object.  You should call 
     * insertObject() to insert the new object into
     * this data source.
     * This implementation attempts to create a new
     * instance of the class returned by 
     * classDescriptionForObjects().
     * Override to return an object specific to 
     * your implementation.
     * @return The newly created object, or null if
     * new objects are not supported by this data source.
     * @see #classDescriptionForObjects
     */
     public Object createObject ()
     {
         Object result = null;
         EOClassDescription c = classDescriptionForObjects();
         if ( c != null )
         {
             result = c.createInstanceWithEditingContext( editingContext(), null );                
         }
         return result;
     }
 
     /**
     * Inserts the specified object into this data source.
     */
     public abstract void insertObject ( Object anObject );
 
     /**
     * Deletes the specified object from this data source.
     */
     public abstract void deleteObject ( Object anObject );
 
     /**
     * Returns the editing context for this data source,
     * or null if no editing context is used.
     * This implementation returns null.
     */
     public EOEditingContext editingContext ()
     {
         return null;
     }
 
     /**
     * Returns a List containing the objects in this
     * data source.  This implementation returns null.
     */
     public NSArray fetchObjects ()
     {
         return null;
     }
 
     /**
     * Returns a data source that is capable of
     * manipulating objects of the type returned by 
     * applying the specified key to objects 
     * vended by this data source.
     * @see #qualifyWithRelationshipKey
     */
     public abstract EODataSource 
         dataSourceQualifiedByKey ( String aKey );
 
     /**
     * Restricts this data source to vend those 
     * objects that are associated with the specified 
     * key on the specified object.
     */
     public abstract void 
         qualifyWithRelationshipKey ( 
         String aKey, Object anObject );
 
     /**
     * Returns the description of the class of the
     * objects that is vended by this data source,
     * or null if this cannot be determined.
     * This implementation returns null.
     */
     public EOClassDescription 
         classDescriptionForObjects ()
     {
         return null;
     }
 
 }
 
 /*
  * $Log$
  * Revision 1.2  2006/02/16 16:47:14  cgruber
  * Move some classes in to "internal" packages and re-work imports, etc.
  *
  * Also use UnsupportedOperationExceptions where appropriate, instead of WotonomyExceptions.
  *
  * Revision 1.1  2006/02/16 13:19:57  cgruber
  * Check in all sources in eclipse-friendly maven-enabled packages.
  *
  * Revision 1.5  2001/05/21 14:02:44  mpowers
  * Corrected javadoc.
  *
  * Revision 1.4  2001/04/27 23:37:20  mpowers
  * Now using EOClassDescription in the EODataSource class, as we should.
  *
  * Revision 1.3  2001/02/27 23:11:07  mpowers
  * Removed object registration from createObject().
  *
  * Revision 1.2  2001/02/16 18:34:19  mpowers
  * Implementing nested contexts.
  *
  * Revision 1.1.1.1  2000/12/21 15:46:38  mpowers
  * Contributing wotonomy.
  *
  * Revision 1.3  2000/12/20 16:25:34  michael
  * Added log to all files.
  *
  *
  */
 

1		/*
2		Wotonomy: OpenStep design patterns for pure Java applications.
3		Copyright (C) 2000 Michael Powers
4
5		This library is free software; you can redistribute it and/or
6		modify it under the terms of the GNU Lesser General Public
7		License as published by the Free Software Foundation; either
8		version 2.1 of the License, or (at your option) any later version.
9
10		This library is distributed in the hope that it will be useful,
11		but WITHOUT ANY WARRANTY; without even the implied warranty of
12		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13		Lesser General Public License for more details.
14
15		You should have received a copy of the GNU Lesser General Public
16		License along with this library; if not, see http://www.gnu.org
17		*/
18
19		package net.wotonomy.control;
20
21		import net.wotonomy.foundation.NSArray;
22
23		/**
24		* EODataSource is used by EODisplayGroup.fetch() to retrieve
25		* a list of objects to display. When a display group has a
26		* data source, the display group will use the data source to
27		* populate the object list and to create new objects to be
28		* displayed in the list, and will update the data source when
29		* objects are inserted or removed from the list. <br><br>
30		*
31		* In certain cases, as when a display group needs to populate
32		* a child display group to show a one-to-many relationship,
33		* the display group will call dataSourceQualifiedByKey to
34		* return a new data source that can vend objects associated
35		* with the specified key and then call qualifyWithRelationshipKey
36		* to specify the object and key that are the source of the
37		* child relationship. <br><br>
38		*
39		* Concrete subclasses are expected to override fetch() and
40		* are required to override insertObject and removeObject.
41		*
42		* @author michael@mpowers.net
43		* @author $Author: cgruber $
44		* @version $Revision: 894 $
45		*/
46	0	public abstract class EODataSource
47		{
48		/**
49		* Creates a new object. You should call
50		* insertObject() to insert the new object into
51		* this data source.
52		* This implementation attempts to create a new
53		* instance of the class returned by
54		* classDescriptionForObjects().
55		* Override to return an object specific to
56		* your implementation.
57		* @return The newly created object, or null if
58		* new objects are not supported by this data source.
59		* @see #classDescriptionForObjects
60		*/
61		public Object createObject ()
62		{
63	0	Object result = null;
64	0	EOClassDescription c = classDescriptionForObjects();
65	0	if ( c != null )
66		{
67	0	result = c.createInstanceWithEditingContext( editingContext(), null );
68		}
69	0	return result;
70		}
71
72		/**
73		* Inserts the specified object into this data source.
74		*/
75		public abstract void insertObject ( Object anObject );
76
77		/**
78		* Deletes the specified object from this data source.
79		*/
80		public abstract void deleteObject ( Object anObject );
81
82		/**
83		* Returns the editing context for this data source,
84		* or null if no editing context is used.
85		* This implementation returns null.
86		*/
87		public EOEditingContext editingContext ()
88		{
89	0	return null;
90		}
91
92		/**
93		* Returns a List containing the objects in this
94		* data source. This implementation returns null.
95		*/
96		public NSArray fetchObjects ()
97		{
98	0	return null;
99		}
100
101		/**
102		* Returns a data source that is capable of
103		* manipulating objects of the type returned by
104		* applying the specified key to objects
105		* vended by this data source.
106		* @see #qualifyWithRelationshipKey
107		*/
108		public abstract EODataSource
109		dataSourceQualifiedByKey ( String aKey );
110
111		/**
112		* Restricts this data source to vend those
113		* objects that are associated with the specified
114		* key on the specified object.
115		*/
116		public abstract void
117		qualifyWithRelationshipKey (
118		String aKey, Object anObject );
119
120		/**
121		* Returns the description of the class of the
122		* objects that is vended by this data source,
123		* or null if this cannot be determined.
124		* This implementation returns null.
125		*/
126		public EOClassDescription
127		classDescriptionForObjects ()
128		{
129	0	return null;
130		}
131
132		}
133
134		/*
135		* $Log$
136		* Revision 1.2 2006/02/16 16:47:14 cgruber
137		* Move some classes in to "internal" packages and re-work imports, etc.
138		*
139		* Also use UnsupportedOperationExceptions where appropriate, instead of WotonomyExceptions.
140		*
141		* Revision 1.1 2006/02/16 13:19:57 cgruber
142		* Check in all sources in eclipse-friendly maven-enabled packages.
143		*
144		* Revision 1.5 2001/05/21 14:02:44 mpowers
145		* Corrected javadoc.
146		*
147		* Revision 1.4 2001/04/27 23:37:20 mpowers
148		* Now using EOClassDescription in the EODataSource class, as we should.
149		*
150		* Revision 1.3 2001/02/27 23:11:07 mpowers
151		* Removed object registration from createObject().
152		*
153		* Revision 1.2 2001/02/16 18:34:19 mpowers
154		* Implementing nested contexts.
155		*
156		* Revision 1.1.1.1 2000/12/21 15:46:38 mpowers
157		* Contributing wotonomy.
158		*
159		* Revision 1.3 2000/12/20 16:25:34 michael
160		* Added log to all files.
161		*
162		*
163		*/
164