001    /**
002     * Copyright 2005-2012 The Kuali Foundation
003     *
004     * Licensed under the Educational Community License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.opensource.org/licenses/ecl2.php
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    package org.kuali.rice.krad.datadictionary.validation.constraint;
017    
018    import java.io.Serializable;
019    
020    
021    /**
022     * This is the marker interface for constraints. Constraints are a central concept in the Rice data dictionary validation, and are the
023     * primary mechanism by which the validation of an object or one of its attributes takes place. For example, by imposing a length constraint
024     * on an attribute of a business object, it's possible to indicate that only values shorter (or longer) than a specific number of characters
025     * are valid for that attribute. 
026     * 
027     * Any interface that extends Constraint is by definition a constraint, and may have one of the following defined:
028     * 
029     * - A sub-interface for {@see Constrainable} that advises on how a constraint maps to data dictionary metadata
030     * - A {@see ConstraintProvider} that looks up constraints for a specific constrainable definition
031     * - A {@see ConstraintProcessor} that processes the constraint against some object value to determine if it is valid
032     * 
033     * @author Kuali Rice Team (rice.collab@kuali.org) 
034     * @since 1.1
035     */
036    public interface Constraint extends Serializable {
037            
038            // Empty - since this is a marker interface, all of the interesting stuff is in interfaces or classes that extend this interface
039            
040    }