View Javadoc
1   /**
2    * Copyright 2005-2014 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.krad.datadictionary.validation;
17  
18  import org.kuali.rice.krad.datadictionary.exception.AttributeValidationException;
19  import org.kuali.rice.krad.datadictionary.validation.capability.Constrainable;
20  
21  import java.util.List;
22  
23  /**
24   * AttributeValueReader defines classes that encapsulate access to both dictionary metadata and object field values
25   *
26   * <p>For example, by reflection
27   * and introspection, for the purpose of performing validation against constraints defined in the
28   * DictionaryValidationService implementation.</p>
29   *
30   * <p>Practically speaking, this interface should only need to be implemented by a small number of classes. The two
31   * major use cases are for
32   * <ol>
33   * <li> a dictionary object with members</li>
34   * <li> a specific member of a dictionary object</li>
35   * </ol>
36   * </p>
37   * <p>
38   * In the first case, implementing classes should provide access to all underlying members of the object via reflection
39   * or some other mechanism.
40   * In the second case, implementing classes only need to provide access to the value associated with that specific
41   * member, and constraints
42   * requiring access to additional members will be skipped.</p>
43   *
44   * @author Kuali Rice Team (rice.collab@kuali.org)
45   * @since 1.1
46   */
47  public interface AttributeValueReader {
48  
49      /**
50       * acts as an accessor for the attribute name that is currently being processed by the DictionaryValidationService
51       * implementation
52       *
53       * @return the current attribute name being processed
54       */
55      public String getAttributeName();
56  
57      /**
58       * provides access to the constrainable attribute definition of a specific attribute name
59       *
60       * <p>If the value of the metadata
61       * associated with the object field does not implement constrainable, or if no metadata is associated with this
62       * object
63       * field,
64       * then null should be returned.</p>
65       *
66       * @param attributeName - the name of the attribute/field whose metadata is being requested
67       * @return dictionary metadata object implementing some constrainable capability
68       */
69      public Constrainable getDefinition(String attributeName);
70  
71      /**
72       * gets a list of all constrainable dictionary metadata definitions for attributes or fields encapsulated by this
73       * object
74       *
75       * @return a list of constrainable definitions
76       */
77      public List<Constrainable> getDefinitions();
78  
79      /**
80       * gets the dictionary metadata associated with an object (its "entry" in the dictionary)
81       *
82       * <p>It can also be constrainable, in which case the object
83       * value itself can be validated against one or more constraints. If the specific entry for the dictionary object
84       * encapsulated by this
85       * reader is not constrainable, or if no entry exists for this dictionary object, or no dictionary object is being
86       * encapsulted, then
87       * null should be returned.
88       * </p>
89       *
90       * @return the constrainable dictionary entry metadata for this object, or null
91       */
92      public Constrainable getEntry();
93  
94      /**
95       * gets the entry name for the purposes of correct error look up
96       *
97       * <p>Errors are generally found by entry name + attribute name + error key</p>
98       *
99       * @return the name that the data dictionary uses to store metadata about this object (not its attributes)
100      */
101     public String getEntryName();
102 
103     /**
104      * looks up a label for a specific attribute name
105      *
106      * @param attributeName - the name of attribute
107      * @return some descriptive label that can be exposed to the end user for error messages
108      */
109     public String getLabel(String attributeName);
110 
111     /**
112      * gets the underlying object itself (not the field/attribute value, but the object)
113      *
114      * @return the object that is being encapsulated by this reader, or null if no object is being encapsulated
115      */
116     public Object getObject();
117 
118     /**
119      * gets the path, which is a string representation of specifically which attribute (at some depth) is being
120      * accessed
121      *
122      * <p>For example, on a person object there might be the following field path:
123      * joe.home.mailingAddress.state</p>
124      *
125      * @return the string representation of the attribute identifier currently being processed
126      */
127     public String getPath();
128 
129     /**
130      * gets the type of the attribute specified - A Java class
131      *
132      * @param attributeName - the name of attribute
133      * @return the type of the attribute referenced by the passed name, or null if no attribute exists of that name
134      */
135     public Class<?> getType(String attributeName);
136 
137     /**
138      * Indicates whether the configured attribute name is readable for the object
139      *
140      * @return boolean if attribute is readable, false if not
141      */
142     public boolean isReadable();
143 
144     /**
145      * looks up the attribute value that is currently being processed
146      *
147      * @param <X> - the type of the attribute
148      * @return the attribute's value if found, null if not
149      * @throws AttributeValidationException
150      */
151     public <X> X getValue() throws AttributeValidationException;
152 
153     /**
154      * looks up any attribute value by name for the object being processed
155      *
156      * @param <X> - the type of the attribute
157      * @param attributeName - the name of attribute whose value is looked up
158      * @return - the attribute's value if found, null if not
159      * @throws AttributeValidationException
160      */
161     public <X> X getValue(String attributeName) throws AttributeValidationException;
162 
163     /**
164      * enables legacy processing of string representations of attribute values like a date range in the format
165      * 12/03/2001..1/29/2009
166      *
167      * @param attributeName - the attribute name
168      * @return the list of token strings for the attribute value of the named attribute
169      * @throws AttributeValidationException
170      */
171     public List<String> getCleanSearchableValues(String attributeName) throws AttributeValidationException;
172 
173     /**
174      * Setter for the current attribute that is being processed
175      *
176      * @param attributeName
177      */
178     public void setAttributeName(String attributeName);
179 
180     /**
181      * overrides {@link Object#clone()}
182      *
183      * @return a cloned {@code AttributeValueReader}
184      */
185     public AttributeValueReader clone();
186 
187 }
188