001 /**
002 * Copyright 2005-2013 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 edu.sampleu.krms.impl;
017
018 import org.kuali.rice.core.api.resourceloader.GlobalResourceLoader;
019 import org.kuali.rice.core.api.uif.RemotableAttributeError;
020 import org.kuali.rice.krms.api.KrmsApiServiceLocator;
021 import org.kuali.rice.krms.api.repository.function.FunctionDefinition;
022 import org.kuali.rice.krms.api.repository.function.FunctionRepositoryService;
023 import org.kuali.rice.krms.api.repository.operator.CustomOperator;
024 import org.kuali.rice.krms.api.repository.type.KrmsTypeDefinition;
025 import org.kuali.rice.krms.api.repository.type.KrmsTypeRepositoryService;
026 import org.kuali.rice.krms.framework.engine.Function;
027 import org.kuali.rice.krms.framework.type.FunctionTypeService;
028 import org.kuali.rice.krms.impl.repository.FunctionBoService;
029
030 import java.text.MessageFormat;
031 import java.util.ArrayList;
032 import java.util.Collection;
033 import java.util.Collections;
034 import java.util.List;
035
036 /**
037 * An example CustomOperator to demonstrate this functionality in of the KRMS UI and engine.
038 *
039 * <p>This one also does the FunctionTypeService duties to produce the engine executable, though that responsibility
040 * could be extracted to a separate class if desired, though that would require more wiring and database configuration.
041 * </p>
042 *
043 * <p>This implementation cheats a bit for easy configuration by persisting the FunctionDefinition on first access.
044 * The only prerequisite configuration to use it: 1) add a KRMS type with namespace "KR-SAP", name "contains operator",
045 * and the serviceName "sampleAppContainsOperatorService". 2) add a type relation of type 'A' (usage allowed) from
046 * your KRMS type to the context type you want to use it with.</p>
047 *
048 * <p>This service implementation is wired up in Spring and exported to the service bus.</p>
049 *
050 * <!-- NOTE: all ID and FK columns in the example SQL below should be replaced appropriately, but you knew that. -->
051 *
052 * <!-- sample SQL for creating the KRMS type:
053 * insert into krms_typ_t (typ_id, nm, nmspc_cd, srvc_nm, actv, ver_nbr)
054 * values ('OPERATOR-KRMS-TYPE-ID', 'contains operator', 'KR-SAP', 'sampleAppContainsOperatorService', 'Y', 1);
055 * -->
056 *
057 * <!-- sample SQL for creating the type relation:
058 * insert into krms_typ_reln_t (typ_reln_id, from_typ_id, to_typ_id, reln_typ, seq_no)
059 * values ('A-UNIQUE-ID', 'CONTEXT-TYPE-ID', 'OPERATOR-KRMS-TYPE-ID', 'A', 1);
060 * -->
061 *
062 * @author Kuali Rice Team (rice.collab@kuali.org)
063 */
064 public class ContainsOperator implements CustomOperator, FunctionTypeService {
065
066 /**
067 * Returns the FunctionDefinition for the custom function the executable portion of this CustomOperator will
068 * call.
069 *
070 * <p>If the FunctionDefinition hasn't been persisted yet, this method will persist it and then return it.</p>
071 *
072 * <p>Note that having the KRMS type for this </p>
073 *
074 * @return
075 */
076 @Override
077 public FunctionDefinition getOperatorFunctionDefinition() {
078 FunctionBoService functionBoService =
079 (FunctionBoService) GlobalResourceLoader.getService("functionRepositoryService");
080
081 KrmsTypeRepositoryService typeRepository = KrmsApiServiceLocator.getKrmsTypeRepositoryService();
082 KrmsTypeDefinition containsOperatorType = typeRepository.getTypeByName("KR-SAP", "contains operator");
083
084 if (containsOperatorType == null) {
085 throw new IllegalStateException("There must be a persisted KRMS type with namespace 'KR-SAP', "
086 + "name 'contains operator', and serviceName 'sampleAppContainsOperatorService'");
087 }
088
089 FunctionDefinition containsFunction = functionBoService.getFunctionByNameAndNamespace("contains", "KR-SAP");
090
091 if (containsFunction == null) {
092 FunctionDefinition.Builder functionBuilder =
093 FunctionDefinition.Builder.create("KR-SAP", "contains", "java.lang.Boolean", containsOperatorType.getId());
094
095 containsFunction = functionBoService.createFunction(functionBuilder.build());
096 }
097
098 return containsFunction;
099 }
100
101 /**
102 * Validate the argument types. This operator supports (String, String), and (Collection, Object). For other
103 * classes, errors will be produced. Note that at the current time (Rice 2.3.1), the rhsClassName will always be
104 * "java.lang.String" since the UI is constrained to set the second arg as a constant value.
105 *
106 * @param lhsClassName the class name for the left hand side operand
107 * @param rhsClassName the class name for the right hand side operand
108 * @return errors
109 */
110 @Override
111 public List<RemotableAttributeError> validateOperandClasses(String lhsClassName, String rhsClassName) {
112 List<RemotableAttributeError> errors = new ArrayList<RemotableAttributeError>();
113
114 if (String.class.getName().equals(lhsClassName)) {
115 if (!String.class.getName().equals(rhsClassName)) {
116 RemotableAttributeError.Builder errorBuilder =
117 RemotableAttributeError.Builder.create("operator", "right hand operand is not a String");
118 errors.add(errorBuilder.build());
119 }
120 } else {
121 try {
122 Class<?> clazz = getClass().getClassLoader().loadClass(lhsClassName);
123
124 if (!Collection.class.isAssignableFrom(clazz)) {
125 RemotableAttributeError.Builder errorBuilder =
126 RemotableAttributeError.Builder.create("operator", "left hand operand is not a Collection");
127 errors.add(errorBuilder.build());
128 }
129 } catch (ClassNotFoundException e) {
130 // it is not a class available to the class loader so we can't determine if it extends Collection or not
131 }
132 }
133
134 return errors;
135 }
136
137 /**
138 * Loads the Function object that the KRMS engine can execute during rule evaluation
139 *
140 * @param functionDefinition {@link FunctionDefinition} to create the {@link Function} from.
141 * @return
142 */
143 @Override
144 public Function loadFunction(FunctionDefinition functionDefinition) {
145 if (!"contains".equals(functionDefinition.getName()) || "KR-SAP".equals(functionDefinition.getNamespace())) {
146 throw new IllegalArgumentException("oops, you have the wrong type service, I can't load this function");
147 }
148
149 // return our KRMS engine executable operator function:
150 return new Function() {
151 @Override
152 public Object invoke(Object... arguments) {
153 if (arguments.length != 2) {
154 throw new IllegalArgumentException("contains operator expects 2 arguments");
155 }
156
157 if (arguments[0] instanceof String) {
158 if (arguments[1] instanceof String) {
159 return Boolean.valueOf(((String)arguments[0]).contains((String)arguments[1]));
160 } else {
161 throw new IllegalArgumentException("if the first argument is a String, the second argument "
162 + "must be as well");
163 }
164 } else if (arguments[0] instanceof Collection) {
165 return Boolean.valueOf(((Collection)arguments[0]).contains(arguments[1]));
166 }
167
168 throw new IllegalArgumentException("argument types must be either (String, String) or (Collection, Object)");
169 }
170 };
171 }
172 }