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1   /**
2    * Copyright 2005-2012 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   * An interface to define classes that encapsulate access to both dictionary metadata and object field values, for example, by reflection
25   * and introspection, for the purpose of performing validation against constraints defined in the DictionaryValidationService implementation. 
26   * 
27   * Practically speaking, this interface should only need to be implemented by a small number of classes. The two major use cases are for 
28   * (1) a dictionary object with members 
29   * (2) a specific member of a dictionary object
30   * 
31   * In the first case, implementing classes should provide access to all underlying members of the object via reflection or some other mechanism. 
32   * In the second case, implementing classes only need to provide access to the value associated with that specific member, and constraints
33   * requiring access to additional members will be skipped. 
34   * 
35   * @author Kuali Rice Team (rice.collab@kuali.org)
36   * @since 1.1
37   */
38  public interface AttributeValueReader {
39  
40  	/**
41  	 * This method is an accessor for the attribute name that is currently being processed by the DictionaryValidationService implementation. 
42  	 * 
43  	 * @return the current attribute name being processed
44  	 */
45  	public String getAttributeName();
46  	
47  	/**
48  	 * This method provides access to the constrainable attribute definition of a specific attribute name. If the value of the metadata 
49  	 * associated with the object field does not implement constrainable, or if no metadata is associated with this object field, 
50  	 * then null should be returned. 
51  	 * 
52  	 * @param attributeName - the name of the attribute/field whose metadata is being requested
53  	 * @return dictionary metadata object implementing some constrainable capability 
54  	 */
55  	public Constrainable getDefinition(String attributeName);
56  	
57  	/**
58  	 * This method returns a list of all constrainable dictionary metadata definitions for attributes or fields encapsulated by this object.
59  	 * 
60  	 * @return a list of constrainable definitions
61  	 */
62  	public List<Constrainable> getDefinitions();
63  	
64  	/**
65  	 * The dictionary metadata associated with an object (its "entry" in the dictionary) can also be constrainable, in which case the object
66  	 * value itself can be validated against one or more constraints. If the specific entry for the dictionary object encapsulated by this 
67  	 * reader is not constrainable, or if no entry exists for this dictionary object, or no dictionary object is being encapsulted, then
68  	 * null should be returned. 
69  	 * 
70  	 * @return the constrainable dictionary entry metadata for this object, or null
71  	 */
72  	public Constrainable getEntry();
73  	
74  	/**
75  	 * An entry name should be returned for the purposes of correcting looking up errors, which are generally found by entry name +
76  	 * attribute name + error key.
77  	 * 
78  	 * @return the name that the data dictionary uses to store metadata about this object (not its attributes)
79  	 */
80  	public String getEntryName();
81  	
82  	/**
83  	 * This method looks up a label for a specific attribute name. 
84  	 * 
85  	 * @param attributeName
86  	 * @return some descriptive label that can be exposed to the end user for error messages
87  	 */
88  	public String getLabel(String attributeName);
89  	
90  	/**
91  	 * The underlying object itself (not the field/attribute value, but the object).  
92  	 * 
93  	 * @return the object that is being encapsulated by this reader, or null if no object is being encapsulated. 
94  	 */
95  	public Object getObject();
96  	
97  	/**
98  	 * The path is a string representation of specifically which attribute (at some depth) is being accessed, for example, on a 
99  	 * person object there might be the following field path:
100 	 * 
101 	 * joe.home.mailingAddress.state
102 	 * 
103 	 * @return the string representation of the attribute identifier currently being processed
104 	 */
105 	public String getPath();
106 	
107 	/**
108 	 * The type of the attribute specified. A Java class. 
109 	 * 
110 	 * @param attributeName
111 	 * @return the type of the attribute referenced by the passed name, or null if no attribute exists of that name
112 	 */
113 	public Class<?> getType(String attributeName);
114 
115     /**
116      * Indicates whether the configured attribute name is readable for the object
117      *
118      * @return boolean if attribute is readable, false if not
119      */
120     public boolean isReadable();
121 	
122 	/**
123 	 * A convenience method for looking up the attribute value that is currently being processed. 
124 	 * 
125 	 * @param <X>
126 	 * @return
127 	 * @throws AttributeValidationException
128 	 */
129 	public <X> X getValue() throws AttributeValidationException;
130 	
131 	/**
132 	 * A method for looking up any attribute value by name for the object being processed. 
133 	 * 
134 	 * @param <X>
135 	 * @param attributeName
136 	 * @return
137 	 * @throws AttributeValidationException
138 	 */
139 	public <X> X getValue(String attributeName) throws AttributeValidationException;
140 	
141 	/**
142 	 * A method to enable legacy processing of string representations of attribute values like a date range in the format 
143 	 * 12/03/2001..1/29/2009 
144 	 * 
145 	 * @param attributeName
146 	 * @return the list of token strings for the attribute value of the named attribute
147 	 * @throws AttributeValidationException
148 	 */
149 	public List<String> getCleanSearchableValues(String attributeName) throws AttributeValidationException;
150 	
151 	/**
152 	 * Setter for the current attribute that is being processed.
153 	 * 
154 	 * @param attributeName
155 	 */
156 	public void setAttributeName(String attributeName);
157     
158     public AttributeValueReader clone();
159 	
160 }
161