001/**
002 * Copyright 2005-2016 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.kew.rule;
017
018import org.apache.log4j.Logger;
019import org.kuali.rice.kew.api.exception.WorkflowException;
020import org.kuali.rice.kew.engine.RouteContext;
021
022import javax.script.ScriptEngine;
023import javax.script.ScriptException;
024import java.util.ArrayList;
025import java.util.List;
026
027/**
028 * An extension of BSFRuleExpression that makes it easier to accumulate a list of responsibilities
029 * to emit. 
030 * 
031 * @author Kuali Rice Team (rice.collab@kuali.org)
032 */
033public class AccumulatingBSFRuleExpression extends BSFRuleExpression {
034    private static final Logger LOG = Logger.getLogger(AccumulatingBSFRuleExpression.class);
035
036    @Override
037    protected void declareBeans(ScriptEngine engine, Rule rule, RouteContext context) throws ScriptException {
038        // define the standard beans
039        super.declareBeans(engine, rule, context);
040        // define our special rule helper class
041        RuleHelper rh = new RuleHelper(rule, context);
042        engine.put("metarule", rh); // backwards compatibility with existing KRAMetaRuleExpression usage
043        engine.put("rulehelper", rh);
044    }
045
046    /**
047     * Helper class that is exposed to groovy scripts
048     */
049    private static final class RuleHelper {
050        private Rule rule;
051        private WorkflowRuleAPI workflow;
052        /**
053         * Responsibilities accumulated during the evaluation
054         */
055        private List<org.kuali.rice.kew.api.rule.RuleResponsibility> responsibilities = new ArrayList<org.kuali.rice.kew.api.rule.RuleResponsibility>();
056        private int responsibilityPriority = 0;
057
058        private RuleHelper(Rule rule, RouteContext context) {
059            this.workflow = new WorkflowRuleAPI(context);
060            this.rule = rule;
061        }
062
063        /**
064         * @return the accumulated responsibilities
065         */
066        public List<org.kuali.rice.kew.api.rule.RuleResponsibility> getResponsibilities() {
067            return responsibilities;
068        }
069
070        /**
071         * @param success whether the result should be successful
072         * @return the RuleExpressionResult with success flag and accumulated responsibilities
073         */
074        public RuleExpressionResult getResult(boolean success) {
075            return new RuleExpressionResult(rule, success, responsibilities);
076        }
077
078        /**
079         * Adds the responsibilities in the result to the list of accumulated responsibilities 
080         * @param result a RuleExpressionResult whose responsibilities to accumulate
081         */
082        public void accumulate(RuleExpressionResult result) {
083            if (result.getResponsibilities() == null || result.getResponsibilities().size() == 0) return;
084
085            Integer curPriority = Integer.valueOf(responsibilityPriority);
086            for (org.kuali.rice.kew.api.rule.RuleResponsibility responsibility: result.getResponsibilities()) {
087                org.kuali.rice.kew.api.rule.RuleResponsibility.Builder builder =
088                        org.kuali.rice.kew.api.rule.RuleResponsibility.Builder.create(responsibility);
089                builder.setPriority(curPriority);
090                responsibilities.add(builder.build());
091            }
092            // increment responsibilityPriority for next rule expression result responsibilities
093            responsibilityPriority++;
094        }
095
096        /**
097         * Evaluates a named rule accumulating responsibilities regardless of rule success
098         * @param ruleName the name of the rule to evaluate
099         * @return whether the rule was successful
100         */
101        public boolean evalRule(String ruleName) throws WorkflowException {
102            RuleExpressionResult result = workflow.invokeRule(ruleName);
103            accumulate(result);
104            return result.isSuccess();
105        }
106
107        /**
108         * Evaluates a named rule and if it is successful accumulates the rule responsibilities
109         * @param ruleName the name of the rule to evaluate
110         * @param accumOnSuccess whether to accumulate the rules responsibilities on success (true), or on failure (false)
111         * @return whether the rule was successful
112         */
113        public boolean evalRule(String ruleName, boolean accumOnSuccess) throws WorkflowException {
114            RuleExpressionResult result = workflow.invokeRule(ruleName);
115            if (accumOnSuccess == result.isSuccess()) {
116                accumulate(result);
117            }
118            return result.isSuccess();
119        }
120
121    }
122}