001/**
002 * Copyright 2005-2018 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 */
016package org.kuali.rice.krad.datadictionary.validation.processor;
017
018import org.kuali.rice.krad.datadictionary.exception.AttributeValidationException;
019import org.kuali.rice.krad.datadictionary.validation.AttributeValueReader;
020import org.kuali.rice.krad.datadictionary.validation.constraint.Constraint;
021import org.kuali.rice.krad.datadictionary.validation.result.DictionaryValidationResult;
022import org.kuali.rice.krad.datadictionary.validation.result.ProcessorResult;
023
024/**
025 * ConstraintProcessor must be implemented by constraint processors, which validate individual constraints in the
026 * data dictionary
027 *
028 * <p>The idea is that each constraint has its own processor, and that the validation service can be configured
029 * via dependency injection with a list of processors. This gives institutions the ability to easily modify how
030 * validation
031 * should be handled and to add arbitrary new constraints and constraint processors.</p>
032 *
033 * <p>An alternative might have been to put
034 * the process() method into the Constraint marker interface and have each Constraint define its own processing, but
035 * that would
036 * have forced business logic into what are naturally API classes (classes that implement Constraint). This strategy
037 * separates
038 * the two functions.</p>
039 *
040 * @param <T> constrainable data type
041 * @param <C> constraint type
042 * @author Kuali Rice Team (rice.collab@kuali.org)
043 */
044public interface ConstraintProcessor<T, C extends Constraint> {
045
046    /**
047     * process the provided constraint
048     *
049     * @param result - holds dictionary validation results
050     * @param value - the value of the attribute
051     * @param constraint - the constraint to process
052     * @param attributeValueReader - - provides access to the attribute being validated
053     * @return the result of the constraint processing
054     * @throws AttributeValidationException
055     */
056    public ProcessorResult process(DictionaryValidationResult result, T value, C constraint,
057            AttributeValueReader attributeValueReader) throws AttributeValidationException;
058
059    /**
060     * gets a descriptive name of this constraint processor
061     *
062     * <p>e.g. @see CollectionSizeConstraintProcessor.CONSTRAINT_NAME</p>
063     *
064     * @return a descriptive name
065     */
066    public String getName();
067
068    /**
069     * gets the java class type of the constraint that this contraint processor handles
070     *
071     * @return an instance of {@code Constraint}
072     */
073    public Class<? extends Constraint> getConstraintType();
074
075    /**
076     * returns true if the processing of this constraint is something that can be opted out of by some pieces of code.
077     * The only example of this in the version under development (1.1) is the existence constraint.
078     *
079     * @return true if this processor can be turned off by some pieces of code, false otherwise
080     */
081    public boolean isOptional();
082
083}