1 /**
2 * Copyright 2005-2011 The Kuali Foundation
3 *
4 * Licensed under the Educational Community License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.opensource.org/licenses/ecl2.php
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.kuali.rice.kew.api.document.attribute;
17
18 /**
19 * Defines the contract for an attribute of a document. These attributes are generally extracted during an indexing
20 * process and stored as key-value pairs associated with the document. In addition to the key-value pair, the
21 * document attribute also defines the data type of data that is held by the attribute.
22 *
23 * <p>This contract simply defines the interface that specific (and strongly typed) implementations of document
24 * attributes will implement. The number of possible implementations of this contract are generally constrainted by
25 * the set of defined {@link DocumentAttributeDataType} enumeration values.</p>
26 *
27 * <p>Concrete instances of should be created using the {@link DocumentAttributeFactory}. It is not generally
28 * of value for a client of the API to create custom implementations of this contract interface.</p>
29 *
30 * @see DocumentAttributeFactory
31 *
32 * @author Kuali Rice Team (rice.collab@kuali.org)
33 */
34 public interface DocumentAttributeContract {
35
36 /**
37 * Returns the name of this document attribute which serves as an identifier for this attribute on the document. A
38 * document may have more then one attribute with the same name, in which case it is treated as a multi-valued
39 * attribute. This method should never return a null or blank value.
40 *
41 * @return the name of the document attribute
42 */
43 String getName();
44
45 /**
46 * Returns the value of this document attribute. It can be of any type as defined by the implementations of this
47 * interface. It is possible that this value may be null in cases where the document has a particular attribute
48 * but no actual value associated with that attribute.
49 *
50 * @return the value of the document attribute
51 */
52 Object getValue();
53
54 /**
55 * Returns the data type of this document attribute. This will generally inform the type of object returned from
56 * the {@code #getValue} method. This method should never return a null value.
57 *
58 * @return the data type of this document attribute
59 */
60 DocumentAttributeDataType getDataType();
61
62 }